Economics

Resources — Inputs used to produce goods and services.

These are the factors of production available in an economy, such as land, labour, capital, and enterprise. Resources are finite, meaning there is a limited supply of them, which contributes to the fundamental economic problem. Think of resources like the ingredients in a kitchen; you only have a certain amount of flour, sugar, and eggs, so you can't bake every cake you want simultaneously.

Needs — Things like food, shelter and clothing that are needed for survival.

Needs are basic requirements for human existence, forming the foundation of an individual's scale of preference. While essential, even needs can be satisfied in various ways, leading to choices. Needs are like the basic functions of a smartphone – calling, texting, internet access – without which it wouldn't be a phone.

Wants — Things that people desire, which are always likely to be something else whatever their income.

Wants are unlimited and continually expanding, developing, and changing, driven by factors like culture, upbringing, life experiences, and observing others. They are distinct from needs, which are essential for survival. Imagine a child in a toy store; they always want the next new toy, even after getting one. This endless desire for more is what economists mean by unlimited wants.

Scarcity — The fundamental economic problem that arises because resources are scarce while people’s wants are unlimited.

Scarcity means that society does not have enough resources to produce all the goods and services necessary to satisfy everyone's wants. This necessitates making choices about how to allocate limited resources. If you have a small garden plot (limited resources) but want to grow every type of fruit, vegetable, and flower imaginable (unlimited wants), you face scarcity and must choose what to plant.

Choice — Taking decisions on how to allocate scarce resources between many competing uses.

Because resources are scarce and wants are unlimited, individuals, firms, and governments must make choices about which wants to satisfy. Every choice made implies foregoing other alternatives. Choosing what to watch on TV when there are many channels available means you are making a choice, and you cannot watch all shows simultaneously.

Opportunity cost — The cost of the choice in terms of the next best alternative.

Whenever a choice is made between alternatives due to scarcity, the opportunity cost is what is given up. It represents the real cost of a decision and is a recurring theme in economics. If you choose to spend your Saturday studying for an exam, the opportunity cost is the next best thing you could have done, like going to a football game with friends.

Scale of preference — Each individual’s scale of preference is a product of a set of influences, including culture, upbringing and life experiences, on which you place your more urgent wants at the top and the less urgent ones at the bottom.

This concept highlights that individuals prioritize their wants based on personal factors, leading to variations in what is considered essential or luxury. It explains why choices differ between people and how these preferences can evolve over time. Imagine making a shopping list for a limited budget. You'd put the absolute necessities like milk and bread at the top, and then less urgent items like a new gadget further down. Your friend's list might be completely different based on their own priorities.

Positive statements — Statements that refer to what will happen, based on actual evidence or observation, without giving an opinion or making a value judgement.

These statements are objective and can be tested or verified against facts. They describe economic phenomena as they are or as they are predicted to be, allowing economists to analyze cause-and-effect relationships. For example, saying 'If you drop a ball, it will fall to the ground' is a positive statement in physics, as it describes an observable fact without personal opinion.

Normative statements — Statements that express an opinion or make a value judgement within their analysis, and therefore can no longer be proven.

These statements are subjective and reflect personal beliefs or ethical positions. They often involve recommendations or evaluations of what 'should' be, rather than what 'is'. For instance, saying 'The government should increase taxes on sugary drinks to improve public health' is a normative statement, as it expresses an opinion about what ought to be done.

Ceteris paribus — A Latin term widely used by economists to refer to a situation where ‘other things remain equal’ or are unchanged.

This assumption allows economists to isolate the effect of a single variable on an outcome, simplifying complex situations for analysis. By holding all other factors constant, the impact of one specific change can be modeled and understood. Imagine testing how a car's speed changes with engine power; ceteris paribus means you assume road conditions, tire pressure, and wind resistance all stay the same, so you can focus only on the engine's effect.

Short run — A time period in which it is possible to change only some inputs, typically when labour can be increased or decreased to change what is produced.

In the short run, at least one factor of production (usually capital) is fixed, while others (like labour) are variable. This means firms can adjust output by changing variable inputs but cannot alter their scale of operations. For example, a bakery in the short run can hire more bakers (labour) to make more bread, but it cannot immediately build a new, larger oven (capital).

Long run — A time period in which it is possible for all factors of production or resources to change.

In the long run, all inputs, including capital, are variable. This allows firms to adjust their scale of operations, build new factories, or adopt new technologies to achieve their objectives more efficiently. In the long run, the bakery can decide to build a larger, more efficient oven or even open a new branch, as all its inputs can be changed.

Very long run — A time period where not only are all factors of production variable but all other key inputs are variable, including technology, government regulations, and social concerns.

This period accounts for fundamental shifts in the economic environment that go beyond just changing traditional factors of production. It considers broader societal and technological changes that influence economic outcomes. In the very long run, the bakery might see the invention of fully automated bread-making robots (technology) or new health regulations that change consumer demand for certain ingredients (social concerns).

Factors of production — The means by which an economy produces a whole range of goods and services to meet the needs of its population.

These are the fundamental resources available in an economy, categorised into land, labour, capital, and enterprise. Owners of these factors receive payments when they are used by others, forming the basis of economic activity. Think of factors of production as the ingredients and tools a chef needs to make a meal: the kitchen (land), the chef's skills (labour), the oven and utensils (capital), and the chef's vision and risk-taking to create a new dish (enterprise).

Land — A natural resource that includes mineral deposits, rivers, lakes, climate, soil for agriculture, trees, and vegetation.

This factor encompasses all natural resources, both above and below the earth's surface, that are used in production. Its quality and quantity are crucial, especially in the context of climate change and resource availability. Imagine a farm: the soil, the water from the rain, the sunlight, and any minerals in the ground are all 'land'. It's not just the physical plot of ground, but all the natural elements it provides.

Labour — The human resources available in any economy.

This factor refers to the physical and mental effort contributed by people to the production of goods and services. Both the quantity (number of workers) and quality (skills, education) of labour are vital for economic progress. In a car factory, the engineers designing the car, the assembly line workers, and the sales staff are all 'labour'. Their collective effort and skills contribute to making and selling the cars.

Capital — A type of physical resource including anything that can be regarded as made by humans to aid production.

This factor comprises man-made goods used to produce other goods and services, such as factories, machinery, and infrastructure. It is combined with land and labour to facilitate production and its quality is particularly important in developing economies. For a baker, 'capital' would be the oven, the mixing machines, the delivery van, and the bakery building itself. These are all man-made tools that help the baker produce bread.

Enterprise — A form of human capital that organises other factors of production and refers to the ability and inventiveness of entrepreneurs who are prepared to take risks.

This factor is crucial for initiating and managing production, involving the entrepreneur's role in combining land, labour, and capital, and bearing the risks associated with business ventures. The reward for enterprise is profit. Think of a film director: they bring together the actors (labour), the set locations (land), the cameras and equipment (capital), and take the financial risk to create a movie. That's enterprise in action.

Human capital — The value of labour in contributing to the productive potential or future growth in an economy, covering the skills, knowledge and experience of labour.

This concept highlights the importance of investing in people's education, training, and health to enhance their productivity and future earnings. It applies to individuals and the population as a whole, driving economic growth. If a carpenter goes to a special course to learn how to build custom furniture, the new skills and knowledge they gain are 'human capital'. This investment makes them more valuable and productive.

Physical capital — The result of more resources being made by businesses and government in the wide range of items such as factories, machinery and infrastructure.

This is the tangible capital used in production, distinct from human capital. Its quality and quantity are often considered a primary source of economic growth, especially in developing countries, by improving productive capacity. The machines in a factory, the roads for transport, and the office buildings are all 'physical capital'. They are tangible assets created by humans to help produce other goods and services.

Specialisation — A situation where individuals and firms, regions and entire economies concentrate on producing some goods and services rather than others.

This process allows entities to focus on what they are best at, leading to increased efficiency and higher output. While it boosts production, it also necessitates exchange or trade as no one becomes self-sufficient. A baker specialises in making bread, while a farmer specialises in growing wheat. Both produce a surplus of their specialty, which they then trade with each other to meet all their needs.

Division of labour — The process of production being broken down into a series of tasks, with each employee carrying out only one or a few of these operations.

This is a specific application of specialisation within a production unit, where workers focus on a single task. It typically leads to increased output per worker, improved quality, and reduced costs, but can also cause worker dissatisfaction. In a car assembly line, one worker might only install the wheels, another might only fit the doors, and another might only paint the car. Each specialises in a small part of the overall process.

market economy — An economic system where resource allocation decisions are largely driven by the market mechanism, with individuals and firms making decisions without government intervention.

In a market economy, the forces of demand and supply, operating through the price mechanism, determine what, how, and for whom goods and services are produced. The government's role is minimal, primarily intervening only in cases of market failure. Imagine a giant farmers' market where every farmer decides what to grow based on what customers want and what prices they can get, and customers decide what to buy based on their needs and the prices offered, with no central authority.

planned economy — An economic system where the government has a central role in all decisions regarding resource allocation, controlling what, how, and for whom goods and services are produced.

In a planned economy, central planning boards set production targets, control prices and wages, and own most productive resources. Consumer preferences and market forces have little to no role in resource allocation. Think of a single, massive company that owns all the factories, farms, and shops in a country, and its CEO (the government) decides exactly what everyone will produce, how much it will cost, and who gets it.

mixed economy — An economic system where both the private sector and public sector play a part in the allocation of resources, involving an interaction between firms, labour, and the government.

Mixed economies combine elements of both market and planned systems, with private ownership of most productive resources alongside some public ownership. Decisions are influenced by both market mechanisms and government intervention. Consider a football game where the players (private sector) largely decide their moves on the field, but there's also a referee (government) who enforces rules, calls fouls, and sometimes makes decisions that affect the flow of the game.

price mechanism — The process by which the forces of demand and supply interact to determine prices and allocate resources in a market economy.

The price mechanism works through changes in prices signaling to producers and consumers where resources are most needed. Excess supply leads to falling prices, discouraging production, while excess demand leads to rising prices, encouraging production. Imagine prices as traffic lights in an economy: a high price is a green light for producers to make more, and a red light for consumers to buy less; a low price is the opposite, guiding resources to where they are most valued.

excess supply — A situation where the quantity supplied of a good or service exceeds the quantity demanded at a given price.

Excess supply results in goods being stockpiled, prompting firms to reduce prices to encourage purchases and clear stocks. This adjustment is a key part of how the price mechanism works to restore equilibrium. Imagine a baker making 100 loaves of bread but only 50 customers want to buy them at the current price; the remaining 50 loaves are excess supply.

market failure — A situation where the price mechanism does not provide the best allocation of resources.

Market failure occurs when the free market fails to allocate resources efficiently, leading to an underprovision of certain goods (like healthcare), non-provision of others (like fire services), or firms exploiting market power for excessive gain. Imagine a broken compass that points in the wrong direction; similarly, market failure means the price mechanism (the 'compass' of the economy) is not guiding resources to their optimal use.

privatisation — The transfer of resources from public ownership to the private sector.

Privatisation is a trend seen in many economies, including former planned economies, as they move towards a mixed economic system. It involves selling state-owned enterprises or assets to private individuals or companies. It's like a public library (government-owned) being sold to a private company that then runs it as a for-profit bookstore.

production possibility curve — A simple economic model that shows the choices available and how resources are allocated, representing the maximum level of output of each of two goods that can be produced.

Also known as the production possibility frontier, it draws a boundary between what can be produced and what cannot. Any point on the curve signifies efficient resource allocation, while points inside indicate inefficiency and points outside are unattainable with current resources. Imagine a baker who can make either cakes or cookies with a fixed amount of flour, sugar, and time. The PPC shows all the combinations of cakes and cookies they can make if they use all their ingredients and time efficiently.

scarcity — A situation where the economy does not have the resources required to achieve a desired level of output of goods.

Scarcity is a fundamental economic problem that necessitates choices about resource allocation. On a PPC diagram, scarcity is represented by any point outside the curve, indicating an unattainable production level. If you only have £10, you face scarcity because you can't buy everything you want; you have to choose what to buy within your budget.

opportunity cost — The benefit given up from the production of one good when resources are reallocated to produce more of another good.

It is the value of the next best alternative forgone. On a PPC, moving from one point to another demonstrates opportunity cost, as producing more of one good requires giving up some production of the other. This cost can be constant (straight-line PPC) or increasing (curved PPC). If you choose to spend your Saturday studying for an exam, the opportunity cost is the fun you could have had going to a party with friends.

trade-off — The process of deciding whether to give up some of one good in order to obtain more of another.

A trade-off is inherent in situations of scarcity where resources are fully utilised. On a PPC, any movement along the curve represents a trade-off, as increasing the production of one good necessitates decreasing the production of another. The numerical extent of a trade-off can be quantified by comparing the changes in production levels. Choosing to spend more time on your part-time job means you have to trade off some study time, or vice versa.

productive capacity — The total ability of an economy to produce goods and services.

This is represented by the position of the production possibility curve. An outward shift of the PPC indicates an increase in productive capacity, while an inward shift indicates a decrease. Changes in resource availability or technology are the main drivers of shifts in productive capacity. Think of a factory's maximum output. If the factory gets new, more efficient machines or hires more skilled workers, its productive capacity increases, allowing it to make more products.

Excludability — A good is excludable (or exclusive) if other consumers can be prevented from using or consuming it.

This characteristic determines if a provider can charge a price for a good and prevent non-payers from using it. For private goods, excludability is typically achieved by charging a price, while non-excludable goods are freely available. For example, a concert ticket is excludable; without it, you cannot enter.

Rivalry — A good is rival if only one person can consume it and in doing so the good is not available for other consumers.

This characteristic describes whether one person's consumption of a good diminishes its availability for others. Most private goods are rivalrous, meaning consumption by one person directly reduces the amount available for others. For instance, eating a slice of pizza is rivalrous; once consumed, it's gone for others.

Private goods — Private goods are also known as economic goods since they have a cost in terms of the resources used and are scarce.

These goods are bought and consumed by individuals or firms for their own benefit and possess the characteristics of excludability and rivalry. A price must be charged for private goods due to their scarcity and the resources used in their production. A smartphone is a private good because it's excludable (you pay for it) and rivalrous (only you can use that specific phone).

Free goods — Free goods have zero opportunity cost since consumption is not limited by scarcity.

These goods have no prices and, in principle, require no factors of production to produce them. They are rare in economics because most goods involve some form of scarcity or resource use. The air we breathe is a free good; it has no price and its consumption by one person doesn't diminish its availability for others.

Public good — A public good has two characteristics: it must be non-excludable and non-rival.

Once a public good is provided for one consumer, it's impossible to stop anyone else from benefiting, and consumption by more people does not reduce the benefit to others. Governments often provide public goods because the free market may fail to do so due to the free rider problem. A lighthouse is a public good, warning all ships (non-excludable) without diminishing the warning for others (non-rival).

Free rider problem — The free rider problem arises where people enjoy the benefits of a public good without having paid for it.

This problem is due to the non-excludability of public goods, making it difficult for private firms to charge for their provision and thus make a profit. Consequently, the free market may not produce public goods even if there is demand. For example, if a private company built a non-toll road, everyone could use it without paying, making it impossible for the company to recover costs.

Quasi-public goods — Some goods that may appear to be public goods do not meet both of these characteristics in full.

These goods possess some, but not all, of the characteristics of a pure public good. They might be non-rivalrous but excludable, or non-excludable up to a point but then become rivalrous due to congestion. A toll road is a quasi-public good; it's non-rivalrous until it becomes congested, but it is excludable because you must pay a toll to use it.

Information failure — Information failure arises because consumers do not recognise how good or bad a particular product is for them: either they do not have the right information or they simply lack some relevant information.

This market failure occurs when consumers make irrational decisions due to incomplete or inaccurate information about the benefits or harmful effects of products. It is a key reason for the underconsumption of merit goods and overconsumption of demerit goods. Not knowing the full health risks of smoking or the long-term benefits of education are examples of information failure.

Merit good — A merit good is a good that is thought to be desirable but which is underprovided by the market.

Merit goods are often underconsumed due to information failure (consumers don't fully recognise their benefits) and low income. Governments tend to provide or subsidise merit goods to encourage their consumption, as they often have positive externalities. Education is a merit good; individuals may not fully appreciate its long-term benefits or cannot afford it, leading to underconsumption.

Demerit good — A demerit good, on the other hand, is seen as any product that is thought to be undesirable and which is overprovided by the market.

Demerit goods are often overconsumed due to information failure (consumers don't fully recognise their harmful effects) and characteristics like being habit-forming, cheap, and readily available. Governments often intervene to reduce their consumption through taxes, regulations, or advertising restrictions. Cigarettes are a demerit good; consumers may not fully understand the long-term health risks, leading to overconsumption.

notional demand — Notional demand refers to buyers wanting a product.

This is the initial desire for a product, without necessarily considering the ability to purchase it. For example, you might have a notional demand for a luxury yacht, meaning you want one, but without the money to buy it, it doesn't become effective demand.

effective demand — Effective demand is notional demand for a product backed by purchasing power.

This is the actual demand that economists refer to, as it represents a real intention to buy, supported by the financial means to do so. Sellers only respond to effective demand. If you want a concert ticket and have the money to buy it, your desire becomes effective demand, and you can actually purchase it.

Demand — Demand refers to the quantity of a product that buyers are willing and able to buy at different prices per period of time, ceteris paribus or other things equal.

This definition highlights that demand is not just about wanting a product, but also having the purchasing power to acquire it. It's measured over a specific time period and assumes all other influencing factors remain constant. Imagine you really want a new video game, but you only have enough money to buy it if it's on sale. Your effective demand only kicks in when the price drops to what you're willing and able to pay.

demand schedule — A demand schedule is a data set that represents consumers’ preferences and the quantity of a product that people are willing and able to buy at various prices per period of time, ceteris paribus.

This table of data forms the basis for plotting a demand curve, showing the inverse relationship between price and quantity demanded. It aggregates individual preferences into a market view. Think of a menu at a restaurant that lists different prices for a dish and how many people would order it at each price – that's like a demand schedule.

demand curve — A demand curve (D) is a graphical representation of the quantity of a product that buyers are willing and able to buy at different prices per period of time, ceteris paribus.

It typically slopes downwards from left to right, illustrating the inverse relationship between price and quantity demanded. It can represent individual or market demand. Imagine a slide at a playground: as the price (height) goes down, more people (quantity demanded) are willing to 'slide' or buy.

normal goods — Normal goods are goods and services for which there is a positive relationship between income and demand.

As consumers' incomes rise, they tend to buy more of these goods, and conversely, demand falls when income decreases. Most products fall into this category. When you get a pay raise, you might buy more restaurant meals or better quality clothing; these are normal goods.

inferior goods — Inferior goods are products for which there is a negative relationship, with less being purchased as income rises.

When income increases, consumers switch away from these goods to higher-quality alternatives. During recessions or income falls, demand for inferior goods tends to increase. If your income increases, you might stop buying cheap packet noodles and instead buy fresh meat and vegetables; the noodles are the inferior good.

Substitutes — Substitutes are alternative goods that satisfy the same want or need.

A change in the price of one substitute is likely to affect the demand for the other. The closer the substitutes, the greater the impact on demand. If the price of Coca-Cola goes up, some consumers might switch to Pepsi because they both satisfy the same thirst; they are substitutes.

Complements — Complements are goods that have a joint demand as they add to the satisfaction that consumers get from another product.

A change in the price or availability of one complementary good will affect the demand for the other. They are consumed together. Cars and petrol are complements; if the price of petrol rises significantly, people might drive less, reducing the demand for cars.

extension of demand — An extension of demand is an increase in the quantity demanded in response to a change in the price of the product.

This is represented by a downward movement along a stationary demand curve. It occurs when the price of the good falls, leading consumers to buy more. If a shop lowers the price of your favourite chocolate bar, you might buy more of them; this is an extension of demand.

contraction of demand — A contraction of demand is a decrease in the quantity demanded in response to a change in the price of the product.

This is represented by an upward movement along a stationary demand curve. It occurs when the price of the good rises, leading consumers to buy less. If the price of cinema tickets goes up, you might go to the cinema less often; this is a contraction of demand.

Supply — Supply refers to the quantity of a product that suppliers are willing and able to sell at different prices over a period of time, ceteris paribus or other things equal.

This definition emphasizes that suppliers must be both willing (motivated by profit) and able (have the resources) to sell. It's measured over a specific time period and assumes other factors are constant. A baker is willing and able to supply more bread if the price per loaf increases, as it becomes more profitable for them.

supply curve — A supply curve (S) is a graphical representation of the quantity of a product that suppliers are willing and able to sell at different prices over a period of time, ceteris paribus.

It typically slopes upwards from left to right, illustrating the positive relationship between price and quantity supplied. It can represent individual firm supply or market supply. Imagine climbing a hill: as the price (height) goes up, producers (quantity supplied) are willing to 'climb higher' or supply more.

extension of supply — An extension of supply is an increase in the quantity supplied in response to a change in the price of the product.

This is represented by an upward movement along a stationary supply curve. It occurs when the price of the good rises, incentivizing producers to supply more. If the price farmers get for their corn increases, they might plant more corn next season; this is an extension of supply.

contraction of supply — A contraction of supply is a decrease in the quantity supplied in response to a change in the price of the product.

This is represented by a downward movement along a stationary supply curve. It occurs when the price of the good falls, making it less profitable for producers to supply as much. If the price of milk falls significantly, dairy farmers might reduce their herd size or supply less milk; this is a contraction of supply.

elasticity — Elasticity measures the responsiveness of one variable (such as quantity demanded for a product) after a change in another variable (such as the price of that product), ceteris paribus.

It is a coefficient that quantifies the extent of change. If a small change in price or income produces a bigger change in quantity demanded, the relationship is elastic; if a large change produces a small change, it is inelastic. Think of a rubber band: a very elastic band stretches a lot with a small pull, while an inelastic band barely stretches even with a strong pull. Similarly, elastic demand changes a lot with a small price change, inelastic demand changes little.

Price elasticity of demand (PED) — Price elasticity of demand (PED) measures the responsiveness of the quantity demanded for a product following a change in the price of the product.

It quantifies how much quantity demanded changes when the product's price changes, assuming all other factors remain constant. A high PED means demand is very sensitive to price changes, while a low PED means it's less sensitive. For example, if a shop raises the price of a common brand of bottled water (high PED), many people will switch to another brand or tap water. If they raise the price of a life-saving medicine (low PED), people will likely still buy it.

price inelastic — Demand is price inelastic when the numerical value of PED is less than 1, meaning the quantity demanded is unresponsive to price changes.

In this case, a percentage change in price leads to a smaller percentage change in quantity demanded. For firms, this means a price increase will lead to an increase in total revenue. Imagine needing petrol for your car; even if the price goes up significantly, you still need to buy it, so your demand doesn't change much. This is price inelastic.

price elastic — Demand is price elastic when the numerical value of PED is greater than 1, meaning the quantity demanded is responsive to price changes.

Here, a percentage change in price leads to a larger percentage change in quantity demanded. For firms, this implies that a price increase will lead to a decrease in total revenue. For example, if a specific brand of chocolate bar increases its price, many consumers will easily switch to a cheaper alternative, showing elastic demand.

perfectly inelastic — Demand is perfectly inelastic when the PED is 0, meaning it is completely unresponsive to price changes.

Regardless of the price charged, consumers are willing and able to buy the exact same amount. This is represented by a vertical demand curve. A person needing a life-saving drug will buy the same quantity regardless of its price, as there are no substitutes and it's essential.

perfectly elastic — Demand is perfectly elastic when the PED is infinite (∞), meaning consumers will buy all that is available at a specific price, but none at a higher price.

Even a tiny increase in price causes quantity demanded to fall to zero, while a tiny decrease causes quantity demanded to become infinite. This is represented by a horizontal demand curve. In a perfectly competitive market, if a single farmer tries to sell wheat above the market price, they will sell nothing, as buyers can easily get identical wheat from other farmers at the market price.

unit elasticity — Demand has unit elasticity when the PED value is (-)1, meaning the percentage change in price is exactly matched by the percentage fall in quantity demanded.

In this scenario, total expenditure by consumers (and total revenue for firms) remains unchanged when the price changes. The demand curve is typically a rectangular hyperbola. If a 10% price increase leads to a 10% decrease in quantity demanded, the total amount of money spent remains the same, like balancing a seesaw perfectly.

Income elasticity of demand (YED) — Income elasticity of demand (YED) measures the responsiveness of the quantity demanded for a product following a change in income.

It indicates how much the quantity demanded of a good changes when consumers' incomes change, assuming other factors are constant. The sign of YED is crucial for classifying goods. For example, if your income doubles, you might buy more restaurant meals (positive YED) but fewer instant noodles (negative YED).

normal good — A normal good is one where the quantity demanded increases as income increases, and its YED is positive and expected to be between 0 and 1.

Most products fall into this category, meaning that as people get richer, they tend to buy more of these goods. Examples include chicken meat in emerging economies or smartphones. As you earn more money, you might buy more clothes or go out to eat more often; these are normal goods.

inferior good — An inferior good is one where the quantity demanded decreases as income increases or increases as income falls, and its YED is negative.

Consumers tend to replace inferior goods with better quality substitutes as their income rises. Examples include poor quality rice or packet noodles. When you get a better job, you might stop buying cheap instant coffee and switch to a more expensive, higher-quality brand. The instant coffee is the inferior good.

necessity good — A necessity good is a type of normal good for which the quantity demanded is unlikely to change significantly when income changes, having a positive YED close to zero.

These are staple foodstuffs or essential items that households purchase regularly, and there's a limit to how much more they will buy even with substantial income increases. Examples include rice, flour, and pulses. Even if your income doubles, you won't suddenly buy ten times more bread or milk; you'll still buy roughly the same amount because you only need so much.

superior or luxury good — A superior or luxury good is a normal good with a positive YED that is greater than 1, meaning the quantity demanded is highly responsive to changes in income.

As incomes rise, the demand for these goods increases more than proportionately. Examples include designer clothes, jewellery, or the latest electronic devices. If you get a big raise, you might decide to buy a luxury car or go on an expensive vacation; these are superior goods because your demand for them increases significantly with income.

Cross elasticity of demand (XED) — Cross elasticity of demand (XED) measures the responsiveness of the quantity demanded for one product following a change in the price of another product.

It quantifies how the demand for product A is affected by a change in the price of product B, assuming other factors are constant. The sign of XED is crucial for determining if goods are substitutes or complements. For example, if the price of coffee goes up, you might buy more tea (positive XED, substitutes). If the price of smartphones goes up, you might buy fewer apps (negative XED, complements).

substitutes — Substitutes are two goods for which the XED is positive, meaning an increase in the price of one good causes an increase in the quantity demanded of the other good.

Consumers can switch between these goods to satisfy a similar want or need. The higher the positive XED, the closer the substitutes. Examples include Coca-Cola and Pepsi Cola. If the price of butter goes up, you might buy more margarine instead; butter and margarine are substitutes.

complements — Complements are two goods for which the XED is negative, meaning an increase in the price of one product causes a decrease in the demand for another product.

These goods are jointly demanded, meaning they are often consumed together. The more negative the XED, the stronger the complementary relationship. Examples include smartphones and apps, or cinema tickets and popcorn. If the price of car fuel goes up significantly, people might drive less, leading to less demand for car washes; fuel and car washes are complements.

Price elasticity of supply (PES) — Price elasticity of supply (PES) measures the responsiveness of the quantity supplied of a product following a change in the price of the product.

It indicates how much the quantity supplied is affected by a change in the product's price, assuming all other factors remain constant. For example, a baker with spare flour and oven capacity can quickly bake more bread if the price goes up, demonstrating elastic supply. A higher PES means producers can easily adjust output in response to price changes.

Price elastic supply — Price elastic supply means that the quantity supplied responds more than proportionately to a change in its price, with a numerical value of PES greater than 1.

This indicates that producers are highly responsive to price changes, able to significantly increase or decrease output. For instance, a T-shirt manufacturer with extra fabric and idle sewing machines can quickly increase production if T-shirt prices rise, demonstrating elastic supply. It often occurs when firms have spare capacity, readily available inputs, or can easily switch production.

Price inelastic supply — Price inelastic supply means that the quantity supplied is proportionately less than the change in price, with a numerical value of PES less than 1.

This indicates that producers are not very responsive to price changes, meaning they cannot easily increase or decrease output. For example, a farmer growing coffee beans cannot quickly increase supply if prices rise, as it takes years for new plants to mature, making their supply inelastic. This is common for goods with limited production capacity, long production times, or scarce inputs.

Perfectly inelastic — Perfectly inelastic supply occurs when it is not possible for a producer to increase or decrease supply, regardless of any change in the price of the product, resulting in a PES of zero.

The supply curve is vertical, indicating that the quantity supplied is fixed at a single amount, irrespective of price fluctuations. For instance, a single, unique antique painting has a perfectly inelastic supply; only one exists, so no matter how high the price goes, no more can be supplied. This is typical for highly perishable goods that must be sold immediately once ready.

Perfectly elastic — Perfectly elastic supply occurs when a producer is only willing to supply products for a given price and no less, resulting in a horizontal supply curve and a PES of infinity (∞).

At this specific price, producers are willing to supply any quantity, but if the price falls even slightly, they will supply nothing. For example, a street vendor selling identical hot dogs might sell unlimited hot dogs at $5,butnoneat$4.99, demonstrating perfectly elastic supply at $5. This is a theoretical extreme, often used to illustrate concepts in perfect competition.

Equilibrium — A market is in equilibrium when the quantity supplied equals the quantity demanded, representing a balanced situation with no tendency to change, ceteris paribus.

At equilibrium, the plans of consumers (demand) match the plans of suppliers (supply), meaning both parties are satisfied with the current price and quantity. The price mechanism ensures the market 'clears', meaning there is no excess supply or demand. Imagine a tug-of-war where both teams are pulling with equal force; the rope is still, representing equilibrium.

Equilibrium price — The equilibrium price is the price at which the quantity demanded equals the quantity supplied in a market.

At this price, there is no pressure for the price to change, as the market 'clears' with no excess supply or demand. It is determined by the intersection of the market demand and supply curves. It's like the 'just right' temperature for a room where everyone feels comfortable – not too hot, not too cold.

Equilibrium quantity — The equilibrium quantity is the quantity of a good or service that is both demanded and supplied at the equilibrium price.

At this quantity, the market is cleared, meaning all goods supplied at the equilibrium price are bought, and all demand at that price is met. It is determined by the intersection of the market demand and supply curves. It's the exact number of sandwiches a shop sells when the price is set so that no sandwiches are left over and no customers leave disappointed due to shortages.

Disequilibrium — Disequilibrium is an imbalance in a market where quantity supplied and quantity demanded are not equal, leading to a tendency for change.

This occurs when the market price is either too high (leading to excess supply) or too low (leading to excess demand). The market mechanism will then adjust prices and quantities until equilibrium is restored. If the tug-of-war teams are not pulling with equal force, one team will be pulled forward, indicating an imbalance or disequilibrium.

Excess supply — Excess supply occurs when the quantity supplied is greater than the quantity demanded at a given price, indicating the clearing price is too high.

This situation leads to unsold stocks for producers. To clear these stocks, suppliers will reduce prices, which in turn encourages more consumers to buy and reduces the quantity supplied, moving the market towards equilibrium. A baker makes too many loaves of bread for the day; the unsold loaves are excess supply.

Excess demand — Excess demand occurs when the quantity demanded is greater than the quantity supplied at a given price, indicating the clearing price is too low.

This situation leads to shortages and unmet orders. Suppliers will recognise this opportunity to increase prices, which discourages some consumers and encourages suppliers to increase quantity supplied, moving the market towards equilibrium. A popular concert has more people wanting tickets than available seats; the extra people wanting tickets represent excess demand.

Normal goods — Normal goods are products for which demand increases as a purchaser's income increases, and decreases as income falls.

Most goods and services fall into this category. An increase in income generally leads to a rightward shift in the demand curve for normal goods, assuming other factors remain constant. If you get a raise at work, you might buy more restaurant meals or better quality clothes; these are normal goods.

Inferior goods — Inferior goods are products for which demand decreases as a purchaser's income increases, and increases as income falls.

Consumers tend to switch from inferior goods to higher-quality or more expensive substitutes when their income rises. An increase in income leads to a leftward shift in the demand curve for inferior goods. If your income increases, you might stop buying instant noodles and instead buy fresh pasta; instant noodles would be an inferior good.

Substitute products — Substitute products are alternative goods that can satisfy the same want or need, so a change in the price of one affects the demand for the other.

If the price of one substitute rises, consumers will switch to the relatively cheaper alternative, causing an increase in demand for the substitute. Conversely, a fall in price of one will decrease demand for its substitute. If the price of Coca-Cola goes up, some people might buy more Pepsi instead; Coca-Cola and Pepsi are substitutes.

Alternative demand — Alternative demand refers to the relationship between substitute goods, where a rise in the price of one product leads to an increase in demand for its alternative.

This occurs because consumers switch their purchasing power to the relatively cheaper alternative when the price of their preferred good increases. It results in a rightward shift of the demand curve for the alternative good. If the price of butter increases, consumers might buy more margarine, as margarine is an alternative.

Complements — Complements are products that are consumed together, so a change in the price of one affects the demand for the other.

A rise in the price of one product will reduce the quantity demanded for it and its associated complement. Conversely, a fall in the price of one will lead to an increase in demand for its complement. If the price of coffee beans falls, people might buy more coffee machines; coffee beans and coffee machines are complements.

Joint demand — Joint demand refers to the relationship between complementary goods, meaning they are consumed together.

An increase in the supply of one good, leading to a fall in its price, will prompt an increase in demand for its complement. This is because the lower price makes the combined consumption more attractive. If the price of cinema tickets falls, people might buy more popcorn, as they are often consumed together.

Derived demand — Derived demand applies where something is required because it is needed for the production of other goods and services.

The demand for a factor of production (like labour or raw materials) is derived from the demand for the final product it helps to create. If demand for the final product increases, demand for the factor of production will also increase. The demand for bricks is derived from the demand for new houses; if more houses are wanted, more bricks are needed.

Joint supply — Joint supply occurs when two goods are produced together from a single productive process, but for different purposes.

An increase in the demand for one of the jointly supplied products will lead to an increase in its supply, which in turn automatically increases the supply of the other jointly supplied product, often leading to a fall in its price. When sheep are raised for wool, meat is also produced; wool and meat are in joint supply.

Rationing — Rationing is a function of the price system where high prices limit the quantity demanded of a product, ensuring it is in line with the quantity supplied to the market.

In a market economy, price acts as an automatic mechanism to allocate scarce resources. Products with high prices, often exclusive ones, are rationed to those willing and able to pay, thus limiting demand. If there's a limited edition pair of sneakers, the very high price rations them to only a few buyers.

Signalling — Signalling is a function of price where changes in price communicate information to both producers and consumers about market conditions.

A rise in price signals to producers that demand has increased and they should produce more, while a fall in price signals that demand has decreased and less should be produced. This helps guide resource allocation. Traffic lights signal to drivers when to stop and go; similarly, prices signal to producers when to increase or decrease production.

Transmission of preferences — Transmission of preferences is a function of the price mechanism that allows the wants of consumers to be made known to producers.

Through their purchasing decisions (or lack thereof), consumers 'vote' with their money, and these signals are transmitted via prices to producers. If a product is not liked or is too expensive, producers receive this message and can react by improving the product or reducing its price. It's like consumers sending a direct message to producers through their shopping carts: 'I like this, make more!' or 'I don't like this, change it!'

Incentive — Incentive is a function of price that motivates buyers and sellers to act in certain ways.

Low prices incentivise consumers to buy more, while high prices incentivise suppliers to produce more for the market. Conversely, high prices discourage consumers, and low prices discourage suppliers, potentially leading them to exit a market. A sale price is an incentive for you to buy a product, just as a high profit margin is an incentive for a company to produce more of that product.

Consumer surplus — Consumer surplus is the difference between the price a consumer is willing to pay for a product and its market price.

This concept highlights that some consumers value a product more than its market price, leading to a 'surplus' benefit. For example, if you'd happily pay $10foryourfavouritecoffeebutitonlycosts$4, your consumer surplus is $6, representing the extra satisfaction you get beyond what you paid.

Producer surplus — Producer surplus is the additional revenue to the airline over and above that for the base line price.

This occurs because some producers are willing to supply a product at a lower price than the market price, gaining extra revenue. For instance, if a farmer is willing to sell wheat for $5tocovercostsbutthemarketpriceis$8, the $3 difference is their producer surplus, representing extra profit.

Market failure — Market failure is an inefficient allocation of goods and services in the market where the free market mechanism does not make the best use of scarce resources.

This occurs when the price mechanism fails to account for all costs and benefits of production or consumption, often due to inefficient production or consumers lacking perfect information. It necessitates government intervention to correct the misallocation. Imagine a group project where everyone only does the parts they enjoy, leading to some crucial parts being left undone or poorly done, and the overall project failing to meet its potential. This is like market failure, where individual self-interest doesn't lead to the best collective outcome.

Public goods — Public goods are goods that are consumed collectively and whose use by one person does not make them less available to others, making it difficult to charge directly for their consumption.

They possess characteristics of non-rivalry and non-excludability, leading to the free rider problem where individuals can benefit without contributing to the cost. Consequently, the private sector has no incentive to provide them, requiring government funding through taxation. Streetlights are a public good; once installed, everyone on the street benefits from the light (non-rivalrous), and you can't stop someone from using the light even if they don't pay for it (non-excludable).

Free rider problem — The free rider problem means that people can enjoy the use of a public good without contributing towards its cost.

This problem arises because public goods are non-excludable, meaning it's impossible to prevent individuals from consuming the good even if they haven't paid for it. This lack of incentive to pay leads to under-provision or non-provision by the private sector. If a neighbour pays for a security camera that covers the whole street, other neighbours might benefit from increased security without paying, 'free riding' on the first neighbour's expense.

Demerit goods — Demerit goods are ones that are considered undesirable for consumers and that tend to be over provided, therefore over consumed in the free market.

Consumers often lack full information about the true costs or negative consequences of consuming demerit goods, leading to overconsumption. Governments intervene through regulations, taxes, or information campaigns to reduce their consumption. Smoking is a demerit good; individuals might not fully appreciate the long-term health costs, leading to overconsumption, which governments try to curb through warnings and bans.

Merit goods — Merit goods are more beneficial to consumers than they may realise, often due to information failure on the part of consumers.

When left to the private sector, merit goods are underprovided because consumers do not fully appreciate their benefits or cannot afford them. Governments intervene through direct provision, subsidies, or legislation to increase their consumption for societal benefit. Education is a merit good; individuals might not fully grasp its long-term benefits for their career and well-being, or might not be able to afford it, so governments often make it compulsory or provide it free.

Ad valorem taxes — Taxes that are a proportion or percentage of the price charged by the retailer.

These taxes are included in the final price paid by consumers and are common for goods like VAT or GST. The amount of tax increases as the price of the good increases, similar to a sales tax where the tax amount depends on how expensive the item is.

Specific taxes — Taxes that are a fixed amount per unit purchased.

These taxes are based on a measurable quantity, such as per litre for fuel, and are included in the final price. They cause a parallel shift of the supply curve, much like a fixed charge per text message regardless of its content or length.

Incidence of an indirect tax — The term used to describe the extent to which the tax burden is borne by the producer, by the consumer or by both.

The distribution of the tax burden depends on the price elasticities of demand and supply. If demand is inelastic, consumers bear more of the burden; if supply is inelastic, producers bear more. This is like two people pushing a heavy box; who feels more strain depends on how firmly each person is planted.

Subsidies — Direct payments made by governments to the producers of goods and services.

Subsidies aim to reduce market prices, encourage consumption of merit goods, or support producers' incomes. They effectively reduce production costs, shifting the supply curve to the right, much like a coupon given to a store by the government for every item sold, allowing the store to sell at a lower price to customers.

Maximum price controls — Legislation imposed by the government to set a maximum price on a particular good or service, also known as price ceilings.

These controls are only effective if set below the free market equilibrium price, aiming to assist low-income families or reduce inequality. They can lead to shortages and the emergence of informal markets, similar to a landlord being legally prevented from charging more than a certain rent.

Minimum price control — Legislation imposed by the government to set a minimum price on a particular good or service, also known as a price floor.

These controls are only effective if set above the free market equilibrium price, often used for demerit goods, agricultural products, or wages. They can lead to excess supply, much like a minimum wage law where employers cannot pay workers less than a certain hourly rate.

Buffer stock scheme — A scheme designed to smooth price rises and falls by buying and selling stocks of products depending on market conditions.

These schemes combine the principles of minimum and maximum price controls, buying up stocks when prices fall below a minimum and selling stocks when prices rise above a maximum, often used for agricultural products. This is like a thermostat that turns a heater on when the temperature drops too low and off when it gets too high, keeping the temperature stable.

Income — Income is the reward for the services of a factor of production.

It is a flow concept, measured over a period, like wages for labour or profits for entrepreneurship. Think of income like the water flowing into a bathtub from the tap; it's a continuous stream over time, providing purchasing power.

Wealth — Wealth describes the stock of assets that someone has built up over time.

These assets, such as property, shares, or businesses, are measured at a specific point in time and can generate future income. Think of wealth like the amount of water already in a bathtub at a given moment; it's a static quantity.

Gini coefficient — The Gini coefficient is a numerical measure of the extent of income inequality in an economy.

It ranges from 0 (perfect equality, where everyone has the same income) to 1 (perfect inequality, where one person has all the income). A lower Gini coefficient indicates a more equal distribution of income, useful for comparing countries or trends. Imagine a pie being shared among friends: 0 means everyone gets an equal slice, 1 means one person gets the whole pie.

Minimum wage rate — A minimum wage rate is a legal requirement of what employers must pay an employee per hour.

This rate, before tax and social security deductions, aims to reduce poverty and income inequality by setting a floor for earnings. It's like a price floor for labour; the government sets a minimum price employers must pay for an hour of work.

Transfer payment — A transfer payment is a payment from tax revenue that is received by certain members of the community.

These payments, such as old age pensions or unemployment benefits, are not made through the market as no production takes place. Their function is to provide a more equitable distribution of income, targeting vulnerable groups. Think of it as the government taking money from taxpayers and putting it into recipients' pockets without goods or services being exchanged for that specific payment.

Progressive income tax — A progressive income tax is a tax system whereby those earning higher incomes are taxed a higher rate or percentage of their income than those on lower incomes.

This system aims to reduce income differentials and promote a more equal distribution of income, as the average rate of tax rises with income. Imagine a ladder where the higher you climb (the more you earn), the larger the percentage of each step (income) you have to give away.

Inheritance tax — Inheritance tax is a tax imposed on individuals who inherit more than a certain amount of wealth.

This policy aims to reduce wealth inequalities by requiring a portion of inherited wealth to be paid to the government. It's like a toll booth on a bridge to receiving inherited wealth; if the value is above a certain amount, a fee is paid to the government.

Capital tax — Capital tax is a tax payable on the financial gain a person may have made in the time that an asset, such as property or a financial portfolio, has been owned.

This tax targets wealth accumulation by taxing the increase in value of assets over time, rather than income. It's like paying a tax on the profit you make when you sell a valuable item that has increased in value since you bought it.

National income — National income is a country’s total output.

It represents the total value of goods and services produced in an economy over a period, typically a year. This output generates income for factors of production, which is then spent on the output, creating a circular flow. Think of a family's total annual earnings from all their jobs and investments; that's their 'family income', similar to a country's national income.

National income statistics — National income statistics is a general term for a number of measures of a country’s economic activity in terms of its output, income and expenditure.

These statistics are crucial for governments and international organisations to assess economic performance, compare countries, and formulate economic policies aimed at stimulating growth and improving living standards. Like a doctor uses various vital signs (heart rate, temperature) to assess a patient's health, economists use national income statistics to assess an economy's health.

Gross domestic product (GDP) — GDP is a measure of the total value of output produced by the factors of production based in a country in a year.

It focuses on the geographical boundaries of a country, including output produced by foreign-owned firms within the country. It is the most widely used measure of national income. Imagine a factory in your town that makes cars. If that factory is owned by a foreign company, the value of the cars it produces still counts towards your town's 'domestic product', not the foreign country's.

Gross national income (GNI) — GNI is the total income earned by the country’s residents and firms regardless of where it is earned.

It includes net property income from abroad, net receipts of compensation of employees, and net taxes less subsidies on products, shifting the focus from output produced domestically to income earned by residents. If you work abroad and send money home to your family, that money contributes to your home country's GNI, even though it wasn't earned within its borders.

Compensation of employees — Compensation of employees is wages earned by workers who are resident in one country but who work abroad for short periods.

This includes income earned by seasonal workers or cross-border commuters who reside in one country but earn their wages in another. These net receipts are added to GDP to calculate GNI. A construction worker living in Mexico but working daily across the border in the US, sending his wages home, contributes to Mexico's GNI through 'compensation of employees'.

Value added — Value added is the difference between the price a firm pays for the goods and services it buys from other firms and the price it sells its product for.

This measure is used in the output method to avoid double counting by only including the new value created at each stage of production, rather than the total value of intermediate goods. A baker buys flour for $1andsellsaloafofbreadfor$3. The 'value added' by the baker is $2,notthefull$3, because the flour's value was already counted.

Transfer payments — Transfer payments are transfers of income from taxpayers to groups of individuals for welfare payments and to firms in the form of subsidies.

These payments are not included in the income or expenditure methods of GDP calculation because they do not represent payment for a good or service produced in the current period; they are simply a redistribution of existing income. Receiving a birthday gift of money is a transfer payment; you didn't 'earn' it by producing something, it was just given to you.

Market prices — Market prices are the prices charged to consumers, including any taxes on products (indirect taxes) and deducting any subsidies that have been given to producers.

These are the actual prices consumers pay in the market. They reflect government intervention through indirect taxes and subsidies, which affect the final price. The price tag you see on a new shirt in a store is its market price, including any sales tax.

Basic prices — Basic prices (also referred to as factor cost) are the prices which would be charged without government intervention and which equal the income paid to the factors of production for making the output.

These prices reflect the true cost of production before any indirect taxes are added or subsidies are deducted. They represent the income earned by the factors of production. Imagine the price a farmer would sell their produce for directly to a distributor, before any government taxes are added or subsidies are applied to the final consumer price.

Gross investment — Gross investment includes the output of capital goods both used to replace existing capital goods that have worn out or become out of date due to advances in technology and capital goods required to expand capacity.

It represents the total spending on new capital goods in an economy. It includes both investment for replacement and investment for expansion. If a company buys a new machine, that's gross investment. It doesn't matter if it's replacing an old machine or adding a new one to increase production.

Depreciation — Depreciation or capital consumption is the value of the replacement capital goods.

It represents the wear and tear or obsolescence of existing capital goods over a period. Subtracting depreciation from gross investment gives net investment, and from gross national income gives net national income. Just like your car loses value over time due to use and age, a country's factories and machines also 'depreciate' and need to be replaced.

Net domestic product (NDP) — Net domestic product (NDP) only includes net investment, deducting the value of replacement capital goods.

NDP is derived from GDP by subtracting depreciation (capital consumption). It provides a more accurate picture of the actual increase in a country's capital stock and its sustainable productive capacity. If a company's gross profit is $100,000but$20,000 was spent replacing old equipment, its 'net profit' (similar to NDP) is $80,000.

Net national income (NNI) — Net national income (NNI) is GNI minus depreciation.

NNI provides a measure of national income that accounts for the consumption of fixed capital (depreciation). It indicates the income available to residents after maintaining the existing capital stock. If your total income (GNI) is $50,000,butyouneedtospend$5,000 to repair your work tools (depreciation), your 'net income' (NNI) is $45,000.

circular flow of income — The circular flow of income model shows how income, spending and output move around an economy.

This model illustrates the interdependence of economic agents such as households, firms, the government, and the international economy, and how economic activity generates a continuous flow of money and goods/services. It explains why GDP can be measured by calculating a country's output, income, or expenditure. Think of a water fountain where water (income/spending) is continuously pumped around.

closed economy — A closed economy is one that does not export or import goods and services.

In a closed economy, all economic activity occurs within national borders, with no international trade. While no economy is truly closed, this model simplifies analysis by excluding the international sector. Consider a self-sufficient island community that produces everything it consumes and doesn't trade with any other islands.

open economy — An open economy is an economy that takes part in international trade.

In an open economy, there are flows of goods, services, and capital across national borders, meaning it exports and imports. This contrasts with a closed economy, which does not engage in international trade. Imagine a house with open windows and doors, allowing people and goods to move freely in and out.

leakages — Leakages are withdrawals from the circular flow of income.

These are parts of income that are not immediately spent on domestically produced goods and services. Common leakages include saving (S), taxation (T), and imports (M), which reduce the amount of money circulating within the domestic economy. Think of a leaky bucket where water (income) is flowing out through holes.

injections — Injections are extra items of spending that add to the circular flow of income.

These are additions to the spending stream that do not originate from current domestic income. Key injections are investment (I), government spending (G), and exports (X), which increase the total spending in the economy. Imagine adding water to a bucket that has some water already.

equilibrium income — For income to be unchanged, injections of extra spending into the circular flow of income must equal leakages from the circular flow.

Equilibrium income occurs when the total amount of money entering the circular flow (injections) exactly balances the total amount leaving it (leakages). At this point, there is no tendency for national income to rise or fall. Consider a balanced scale where the weight on one side (injections) equals the weight on the other (leakages).

disequilibrium — Disequilibrium occurs when injections are not equal to leakages in the circular flow of income.

If injections are greater than leakages, there will be extra spending, causing income to rise. Conversely, if leakages exceed injections, more spending will leave the circular flow, and income will fall, moving the economy away from its previous equilibrium. If a balanced scale suddenly has more weight added to one side, it becomes unbalanced or in disequilibrium.

Aggregate demand (AD) — Aggregate demand (AD) in economics is used to describe the total spending of consumers (households), firms and the government plus foreigners’ spending on the country’s exports minus spending by the country’s consumers, firms and government on imports.

AD represents the total demand for all goods and services produced in an economy at a given price level. It is composed of consumption, investment, government spending, and net exports. Think of aggregate demand as the total shopping cart of an entire country, including everything everyone in the country buys, plus what foreigners buy from the country, minus what the country buys from abroad.

Consumer expenditure — Consumer expenditure (also called consumer spending or consumption) is spending by households on goods and services to satisfy current wants, for example, spending on food, clothing, travel and entertainment.

This is the largest component of aggregate demand and is primarily influenced by disposable income. Imagine all the money spent by every household in a country on everyday items and services, from groceries to haircuts, that's consumer expenditure.

Saving — Saving is defined as disposable income minus consumer expenditure.

Saving represents the portion of disposable income that is not spent on consumption. It can be held in bank accounts or other financial assets and is a source of funds for investment. If your weekly allowance is your disposable income, and you spend some on snacks, the money you put aside for a bigger purchase later is your saving.

Investment — Investment includes private sector spending by firms on capital goods, such as factories, offices, machinery and delivery vehicles.

This component of AD is crucial for an economy's long-term growth as it increases productive capacity. It is influenced by consumer demand, interest rates, technology, cost of capital, expectations, and government policy. Think of a baker buying a new, more efficient oven for their bakery; that's investment – spending on something that will help produce more in the future.

Government spending — Government spending includes expenditure on providing merit goods, such as education and healthcare, and public goods, such as defence.

This component of AD is determined by government policy, tax revenue, and demographic changes. It can be used to stimulate economic activity or provide essential services. Imagine the government building new roads, funding schools, or paying for national defence; all these are examples of government spending contributing to aggregate demand.

Net exports — Net exports are foreigners’ spending on the country’s exports minus spending by the country’s consumers, firms and government on imports.

This component reflects the balance of trade and is influenced by a country's GDP, other countries' GDPs, relative price and quality competitiveness, and the exchange rate. A positive value adds to AD, while a negative value subtracts. If a country sells more goods to other countries than it buys from them, it has positive net exports, like a shop that sells more than it buys from suppliers.

Aggregate demand (AD) curve — The aggregate demand (AD) curve shows the different quantities of total demand for the economy’s products at different prices.

It slopes downwards due to the wealth effect (reduced purchasing power of savings), the international effect (exports become less competitive, imports more competitive), and the interest rate effect (higher prices increase demand for money, raising interest rates and reducing C and I). Imagine the total amount of goods and services everyone in a country wants to buy. If prices generally go up, people feel poorer, foreign goods look cheaper, and borrowing becomes more expensive, so they buy less overall.

Aggregate supply (AS) — Aggregate supply (AS) is the total planned supply of all the producers in the country.

AS represents the total quantity of goods and services that firms are willing and able to produce and sell at a given price level. It is often differentiated into short-run (SRAS) and long-run (LRAS). Think of aggregate supply as the total amount of goods and services that all the factories, farms, and service providers in a country are collectively willing to produce.

Short-run aggregate supply — Short-run aggregate supply is the output that will be supplied in a period of time when the prices of factors of production (inputs, resources) have not had time to adjust to changes in aggregate demand and the price level.

The SRAS curve slopes upwards because as the price level rises, firms' profits increase (due to sticky input prices), average costs may rise with increased output, and producers may misinterpret general price rises as relative price rises for their products. Imagine a factory that can quickly increase production by having workers do overtime, but their wages (input costs) don't immediately go up; they'll produce more if they can sell at higher prices.

Long-run aggregate supply — Long-run aggregate supply is the output that will be supplied in the time period when the prices of factors of production have fully adjusted to changes in aggregate demand and the price level.

In the long run, all input prices are flexible, so the economy's output is determined by its productive potential (quantity and quality of resources), not the price level. Its shape differs between Keynesian and new classical views. Think of the maximum sustainable output a country can produce if all its resources are fully and efficiently employed, regardless of how much money is circulating.

Macroeconomic equilibrium — The equilibrium level of output and the price level are determined where aggregate demand is equal to aggregate supply.

This is the point where the AD and AS curves intersect, representing a stable state where the total quantity of goods and services demanded equals the total quantity supplied. Any deviation from this point will lead to market forces pushing the economy back to equilibrium. Imagine a tug-of-war between all the buyers (AD) and all the sellers (AS) in an economy; macroeconomic equilibrium is when the forces are balanced.

Real output — Real output refers to the level of goods and services produced in an economy, adjusted for inflation.

It is a measure of the actual volume of production, reflecting the economy's productive capacity and resource utilization, rather than just the monetary value of output. It is often represented by real GDP. If you produce 10 apples this year and 12 apples next year, your real output of apples has increased, regardless of whether the price of apples changed.

Price level — The price level refers to the average of current prices across the entire spectrum of goods and services produced in an economy.

It is a measure of the overall level of prices, often represented by a price index like the Consumer Price Index (CPI) or GDP deflator. Changes in the price level indicate inflation or deflation. Think of the price level as the average cost of a typical shopping basket for everyone in the country; if that average cost goes up, the price level has risen.

Economic growth — Economic growth is an increase in an economy’s output.

It is a key indicator of macroeconomic performance, measured as the annual percentage change in output. For people to enjoy more goods and services, output must increase by more than population growth, leading to an increase in GDP per head. Imagine a baker who makes more loaves of bread this year than last year; the increase in the number of loaves represents economic growth for their bakery.

Nominal (or money) GDP — Nominal (or money) GDP is GDP measured in terms of the prices operating in the year in which output is produced.

It is also referred to as GDP at current prices and is a measure that has not been adjusted for changes in the price level. A rise in nominal GDP can be misleading as it may reflect only price increases, not actual output increases. If you earn $100thisyearand$110 next year, your nominal income has increased. But if prices also rose by 10%, your real purchasing power hasn't changed.

Real GDP — To calculate real GDP, economists measure GDP at constant prices (the prices operating in a selected year).

This ensures the effect of inflation, which distorts nominal GDP, is removed, providing a truer picture of changes in actual output. It is calculated by adjusting nominal GDP using a price index. If a baker sells 100 loaves for $5each($500 total) and next year sells 100 loaves for $6each($600 total), their nominal revenue increased. But if we use last year's prices, their real revenue (output) remained $500, showing no real growth.

GDP deflator — The price index used to convert nominal into real GDP is called the GDP deflator, which measures the prices of products produced, rather than consumed, in a country.

It includes the prices of capital goods as well as consumer products and includes the price of exports but excludes the price of imports. This makes it a comprehensive measure of price changes for domestically produced goods and services. Think of the GDP deflator as a special magnifying glass that shows you how much of the change in GDP is due to actual growth in production versus just rising prices for everything made in the country.

Recession — A decline in real GDP over two consecutive quarters (six months) or more is called a recession.

A country's output may decline as a result of a decrease in aggregate demand or a decrease in aggregate supply. It signifies a significant contraction in economic activity. Imagine a car that usually travels at 60 mph, but for two months in a row, its speed drops to 40 mph or less; that sustained slowdown is like a recession for the car's journey.

Unemployment — Unemployment occurs when people who are willing and able to work cannot find a job.

This definition specifically excludes individuals not seeking employment, such as children, retirees, students, or homemakers. The unemployed are considered part of the labour force, representing an unused economic resource, much like idle machines in a factory ready to produce but lacking orders.

Economically inactive — People who are not working and trying to find employment are said to be economically inactive.

This group includes individuals of working age who are not part of the labour force, such as full-time students, early retirees, homemakers, or those too unwell to work. They are distinct from the unemployed because they are not actively seeking employment, similar to spectators in a sports stadium who are present but not participating in the game.

Economically active — Anyone in the labour force is said to be economically active.

This group comprises all people who can contribute to the production of goods and services, including both those currently employed and those who are unemployed but actively seeking work. They represent the available human resources in an economy, much like all the students and teachers actively participating in learning and teaching in a school.

Labour force — The labour force in an economy is defined as the total number of workers who are available for work.

It includes all people who are employed and those who are unemployed but actively seeking employment. The size of a country's labour force is influenced by demographic, economic, social, and cultural factors, similar to a football team's squad which includes players on the field and those on the bench ready to play.

Labour force participation rate — The labour force participation rate refers to the percentage of the total population of working age who are actually classified as being part of the labour force.

This rate indicates the proportion of the potential workforce that is either employed or actively seeking employment. Factors like higher education participation or early retirement can influence this rate. For example, if 60 out of 100 working-age students are working or looking for a job, the rate is 60%.

Level of unemployment — The level of unemployment refers to the total number of workers who are unemployed.

This is an absolute figure, representing the raw count of individuals without jobs but willing and able to work. It provides a snapshot of the total number of people affected at a specific point in time, like counting the exact number of empty seats in a cinema.

Unemployment rate — The unemployment rate is the number of unemployed people as a percentage of the labour force.

This is a key indicator of the health of an economy, showing the proportion of the available workforce that is not employed. It allows for easier comparison between different economies or over time, similar to how an absence rate of 10% means 10 out of 100 students are absent.

Claimant count measure — The claimant count measure counts as unemployed those who register as unemployed in order to claim unemployment benefits.

This method is relatively cheap and quick to calculate as it uses existing administrative data. However, it may not accurately reflect the true extent of unemployment, potentially overstating or understating the figure, much like counting people who sign up for a free meal, which might miss some in need or include some not truly in need.

Labour force survey measure — The labour force survey measure involves conducting a survey asking people if they are employed, unemployed or economically inactive.

This method typically uses the International Labour Organisation (ILO) definition of unemployment, which includes people of working age without work, available for work, and seeking paid employment. It is generally considered more comprehensive and suitable for international comparisons, similar to conducting a thorough door-to-door census.

Discouraged workers — Discouraged workers are people who leave the labour force because they give up on the chances of finding a job.

These individuals were previously unemployed and actively seeking work but have become so disheartened by their lack of success that they stop looking. They are then classified as economically inactive, which can artificially lower the official unemployment rate, much like someone giving up on catching a bus that never comes.

Frictional unemployment — Frictional unemployment is unemployment that arises when workers are between jobs.

This type of unemployment is short-term and unavoidable in a dynamic economy, as people naturally take time to search for new jobs after leaving or losing old ones. It includes voluntary, search, casual, and seasonal unemployment, much like the brief pause between two songs on a playlist.

Voluntary unemployment — Voluntary unemployment occurs when workers are not willing to accept jobs at the current wage rate and working conditions.

This is a form of frictional unemployment where individuals choose to remain unemployed, often because they are holding out for better pay or conditions, or because unemployment benefits are sufficiently high to disincentivise taking low-wage jobs. An example is refusing a cashier job because one believes they can find a better-paying manager role.

Search unemployment — Search unemployment arises when workers do not accept the first job or jobs on offer, but spend some time looking for a better-paid job.

This is another form of frictional unemployment, where individuals invest time and effort in searching for a job that best matches their skills and preferences, rather than taking the first available position. Improved labour market information can reduce this, similar to shopping for a new phone by comparing models and prices.

Casual unemployment — Casual unemployment refers to workers who are out of work between periods of employment including, for example, actors, supply teachers and construction workers.

This is a type of frictional unemployment common in industries with irregular or project-based work. Workers in these sectors frequently move between short-term contracts, leading to intermittent periods of unemployment, much like a freelance photographer between gigs.

Seasonal unemployment — Seasonal unemployment occurs when demand for workers fluctuates according to the time of the year.

This type of frictional unemployment affects industries like tourism, agriculture, and construction, where activity levels vary significantly with the seasons. Workers are employed during peak seasons and laid off during off-peak times, similar to staff at a ski resort being laid off in summer.

Structural unemployment — Structural unemployment arises due to changes in the structure of the economy.

This occurs when there is a mismatch between the skills, qualifications, experience, or geographical location of unemployed workers and the requirements of available job vacancies. It is often long-term and can result from technological advancements, shifts in consumer demand, or international competition, like miners becoming unemployed when a coal mine closes and new jobs are for software engineers.

Regional unemployment — Regional unemployment occurs when declining industries are concentrated in a particular area or areas of the country.

This is a form of structural unemployment where a specific region experiences high unemployment due to the decline of its dominant industry, leading to a lack of suitable job opportunities for the local workforce. An example is a town experiencing high unemployment after a major car manufacturing plant closes.

Technological unemployment — Technological unemployment occurs when people are out of work due to the introduction of labour-saving techniques.

This is a type of structural unemployment where automation, robotics, or other technological advancements replace human labour, leading to job losses in affected industries. Workers may need to acquire new skills to find employment, such as cashiers losing jobs due to self-checkout machines.

International unemployment — International unemployment occurs when workers lose their jobs because demand switches from domestic industries to more competitive foreign industries.

This is a form of structural unemployment resulting from globalisation and international trade. Domestic industries may decline due to cheaper imports or foreign competition, leading to job losses in the home country, for instance, steel workers losing jobs because consumers buy cheaper foreign steel.

Cyclical unemployment — Cyclical unemployment or demand-deficient unemployment, arises due to a lack of aggregate demand.

This type of unemployment affects the whole economy during economic downturns or recessions, as firms reduce output and lay off workers due to insufficient consumer spending and investment. It is often widespread across various industries, similar to a restaurant cutting staff hours during a slow season due to fewer customers.

Demand-deficient unemployment — Demand-deficient unemployment arises due to a lack of aggregate demand.

This is another term for cyclical unemployment, emphasising that the root cause is insufficient overall spending in the economy. When aggregate demand falls, firms reduce production and consequently require less labour, leading to job losses, such as car manufacturers laying off workers if everyone stops buying new cars.

Price stability — Price stability occurs when prices rise by only a small percentage and there is an avoidance of fluctuations in the price level.

Governments aim for price stability because a low and stable inflation rate can encourage firms to expand, leading to higher national output, employment, and increased availability of goods and services for public spending. Imagine driving a car at a steady, comfortable speed on a smooth road, rather than constantly speeding up and slowing down or hitting potholes. Price stability is like that smooth ride for an economy.

Inflation — Inflation means that, on average, prices are rising at a particular rate.

When the price level increases, the value of money falls, and its purchasing power declines, meaning each unit of currency buys less than before. It does not mean every price is rising or at the same rate. Think of your pocket money: if prices for your favourite snacks go up, your pocket money buys fewer snacks than it used to, even if the amount of money hasn't changed.

Hyperinflation — Hyperinflation is generally considered to be an inflation rate that exceeds 50% a month, but the rate of inflation can go much higher.

This occurs when inflation gets out of control, often leading people to resort to barter as money loses its value rapidly, and usually necessitates the replacement of the currency. Imagine trying to buy a cup of coffee, and by the time you reach the counter, the price has doubled from what it was an hour ago. That's the extreme speed of price changes in hyperinflation.

Deflation — Deflation generally refers to a sustained fall in the price level.

This results in a rise in the value of money, with each currency unit having greater purchasing power, and involves a negative inflation rate. If you save up for a new gadget and then its price drops significantly, your savings can now buy more than you initially expected. That's like deflation for your money's purchasing power.

Disinflation — Disinflation occurs when the inflation rate falls but is still positive.

In this case, the price level is still rising, but at a slower rate than before, meaning the rate of increase in prices is slowing down. Imagine a car that was accelerating very quickly, but then starts to accelerate less quickly, even though it's still gaining speed. It's still moving faster, just not as rapidly as before.

Money values — Money values, or nominal values, are the values of the prices operating at the time.

These values are not adjusted for inflation, representing the raw monetary figures without considering changes in purchasing power. If you earned $100lastyearand$110 this year, $100and$110 are your money values. They don't tell you if you can buy more or less.

Nominal values — Nominal values, or money values, are the values of the prices operating at the time.

These values are not adjusted for inflation, representing the raw monetary figures without considering changes in purchasing power. If you earned $100lastyearand$110 this year, $100and$110 are your nominal values. They don't tell you if you can buy more or less.

Real data — Real data is data in real terms, which has been adjusted for inflation.

This adjustment allows for a true comparison of purchasing power over time by removing the effect of price level changes. If your wages rose by 20% but inflation was 25%, your real wages actually fell. Real data tells you what you can *actually* buy, not just the number on your paycheck.

Demand-pull inflation — Demand-pull inflation occurs when prices are 'pulled up' by increases in aggregate demand that are not matched by equivalent increases in aggregate supply.

This can result from a rise in consumer expenditure, government spending, investment, or net exports, especially when the economy is close to full capacity. Imagine a very popular new toy that everyone wants. If there aren't enough toys to go around, the store can raise the price because demand is so high.

Cost-push inflation — Cost-push inflation occurs when prices are pushed up by increases in the cost of production.

This type of inflation is typically caused by factors like rising wages (more than productivity), increased raw material or fuel costs, a fall in the exchange rate making imports more expensive, or increased profit margins. Imagine a baker whose flour and sugar costs suddenly double. To maintain profit, they have to raise the price of their bread, even if demand hasn't changed.

Menu costs — Menu costs are the costs involved in changing prices.

These costs affect firms, requiring changes to catalogues, price tags, bar codes, and advertisements, and also involve staff time and can be unpopular with customers. Think of a restaurant having to print new menus every week because food prices keep changing. That's a direct cost of inflation.

Shoe leather costs — Shoe leather costs are the costs involved in moving money from one financial institution to another in search of the highest rate of interest.

These costs arise as individuals and firms spend more time and effort managing their money to minimise the erosion of its value by inflation, leading to less efficient use of resources. Imagine literally wearing out your shoes walking from bank to bank to find the best interest rate to protect your savings from losing value. It's the effort and time spent on financial management.

Fiscal drag — Fiscal drag (also known as 'bracket creep') occurs when the income levels corresponding to different tax rates are not adjusted in line with inflation.

As a result, people and firms are 'dragged' into higher tax brackets even if their real income has not increased, leading to a higher proportion of their income being paid in tax. Imagine a ladder where the rungs (tax brackets) stay in the same place, but the ground (your income) keeps rising due to inflation. You'll climb to a higher rung and pay more tax, even if you can't buy more.

Bracket creep — Bracket creep (also known as 'fiscal drag') occurs when the income levels corresponding to different tax rates are not adjusted in line with inflation.

As a result, people and firms are 'dragged' into higher tax brackets even if their real income has not increased, leading to a higher proportion of their income being paid in tax. Imagine a ladder where the rungs (tax brackets) stay in the same place, but the ground (your income) keeps rising due to inflation. You'll climb to a higher rung and pay more tax, even if you can't buy more.

Inflationary noise — Inflationary noise (also called 'money illusion') arises when inflation causes consumers and firms to confuse price signals.

It makes it difficult to assess what is happening to relative prices, potentially leading consumers and firms to make incorrect decisions, such as increasing output when a price rise is due to inflation rather than increased demand. Imagine trying to hear a specific conversation in a very noisy room. Inflation is the 'noise' that makes it hard to distinguish real changes in demand or supply (the conversation) from general price increases.

Money illusion — Money illusion (also called 'inflationary noise') arises when inflation causes consumers and firms to confuse price signals.

It makes it difficult to assess what is happening to relative prices, potentially leading consumers and firms to make incorrect decisions, such as increasing output when a price rise is due to inflation rather than increased demand. Imagine trying to hear a specific conversation in a very noisy room. Inflation is the 'noise' that makes it hard to distinguish real changes in demand or supply (the conversation) from general price increases.

Good deflation — Good deflation occurs as a result of an increase in aggregate supply.

This type of deflation leads to a fall in the price level and a rise in real GDP, often driven by advances in technology or lower production costs, which can also increase employment and international competitiveness. Imagine a new invention makes producing smartphones much cheaper and more efficient. Prices fall, but more people can afford them, so more are sold, and the economy grows.

Bad deflation — Bad deflation takes place when the price level is driven down by a fall in aggregate demand.

This type of deflation results in falling output, potentially higher unemployment, and runs the risk of developing into a deflationary spiral where consumers delay purchases, firms reduce investment and employment, and debt burdens increase. Imagine a town where everyone suddenly loses their jobs and stops buying things. Shops lower prices to attract customers, but no one has money, so demand keeps falling, and more businesses close.

Price Stability — A low and stable inflation rate.

Governments aim for price stability, meaning a low and stable positive inflation rate, rather than zero inflation. This is because inflation measures tend to overstate price rises, aiming for zero could lead to deflation, and a small, stable price increase encourages firms to boost output. Achieving price stability is like maintaining a steady speed on a motorway; a constant, low speed is safe and allows for progress.

Inflation Target — A target for the inflation rate, set by a government for its central bank to achieve.

An inflation target makes a central bank more accountable for maintaining price stability and can reduce inflationary expectations. If firms and workers have confidence in the target, they may act in ways that do not push up prices, such as demanding lower wage rises. An inflation target is like a thermostat for the economy, with the central bank adjusting policy to keep the economy from getting too hot or too cold.

Low Unemployment — A state of having a low proportion of the labour force unemployed.

Low unemployment is a key objective because it leads to high output, high tax revenue for the government, and low government expenditure on unemployment benefits. Governments are also concerned with the quality of employment, ensuring jobs are skilled, secure, and well-paid, and that any unemployment is short-term to prevent workers from losing skills. A football team manager aims for low unemployment by wanting all their best players on the pitch contributing.

Economic Growth — An increase in a country’s output.

Governments pursue economic growth to prevent rising unemployment and to allow living standards to rise. However, they aim for a sustainable rate, as too high a rate can cause the economy to overheat, leading to inflation and risky investments. Pursuing economic growth is like tending a plant; you want it to grow steadily, not wither or scorch.

Overheating — A situation where an economy's aggregate demand increases faster than its aggregate supply.

Overheating can happen when there is too high a rate of economic growth, putting pressure on resources and causing inflationary pressure to build up. It can also encourage over-optimistic entrepreneurs and households to take on loans they may struggle to repay. An overheating economy is like a car engine running in the red zone, putting immense strain on its parts.

Fiscal policy — Fiscal policy is the use of taxation and government spending to manage aggregate demand in order to achieve the government’s macroeconomic aims.

It is the government's primary tool for influencing the economy, aiming to achieve objectives like economic growth, low inflation, and full employment. Think of fiscal policy as a car's accelerator and brake pedals: government spending is the accelerator to boost demand, and taxation is the brake to slow it down, both used to steer the economy towards its goals.

budget deficit — A budget deficit occurs when government spending exceeds tax revenue.

This means the government is spending more than it collects in taxes, requiring it to borrow money, which adds to the national debt. It typically has an expansionary effect on aggregate demand. If you spend more than you earn in a month, you have a deficit and need to borrow money or use savings to cover the difference.

budget surplus — A budget surplus arises when tax revenue exceeds government spending.

This indicates that the government is taking in more money than it is spending, which can be used to pay off national debt or save for future needs. It typically has a contractionary effect on aggregate demand. Imagine your personal budget: if you earn more than you spend in a month, you have a surplus, which you can save or use to pay off loans.

balanced budget — A balanced budget is when government spending matches tax revenue.

Most governments aim to achieve a balanced budget over time, as it implies fiscal sustainability without adding to or reducing the national debt. It suggests a neutral impact on aggregate demand. It's like breaking even on your monthly finances – your income exactly covers your expenses.

cyclical deficit — A budget deficit that occurs due to a fall in economic activity is known as a cyclical deficit.

During a recession, tax revenues automatically fall (due to lower incomes and profits) and government spending on benefits automatically rises (due to higher unemployment), leading to a deficit without deliberate policy changes. It is expected to disappear as economic activity increases. Think of it like your income dropping when you're temporarily out of work – your spending might exceed your reduced income, but it's expected to balance out once you're employed again.

structural deficit — A structural deficit arises when a government is committed to too much spending relative to its tax revenue.

This type of deficit will not disappear even when GDP increases to its full employment level, indicating a fundamental imbalance between government spending commitments and its revenue-raising capacity. It requires deliberate policy changes to address. This is like having a fixed monthly expense (e.g., a high rent) that consistently exceeds your regular income, regardless of any temporary bonuses you might get. You need to fundamentally change your spending or income.

national debt — Government or public sector debt is the total debt a central government, or the whole public sector, has built up over time.

It is the accumulation of past budget deficits minus any budget surpluses. A large national debt can lead to significant interest payments, opportunity costs, and may make future borrowing more difficult or expensive. If a budget deficit is like your credit card bill for one month, the national debt is the total outstanding balance on all your credit cards and loans combined over many years.

Direct taxes — Direct taxes are taxes on income and wealth.

These are paid directly by individuals or firms to the government. Examples include income tax and corporate tax. They are typically progressive and can be used to redistribute income. The tax taken directly from your paycheck or a company's profits before they are distributed is a direct tax.

income tax — Income tax is a tax on the income of individuals.

It is a primary source of government revenue and is often progressive, meaning higher earners pay a larger percentage of their income in tax. It can influence labour supply and disposable income. The portion of your salary that is automatically deducted and sent to the government is income tax.

corporate tax — Corporate tax is a tax on the profits of firms.

It is a direct tax that affects firms' retained earnings and their incentive to invest. Changes in corporate tax rates can influence business investment and location decisions. It's like a portion of a company's annual earnings being paid to the government before any dividends are distributed to shareholders.

Indirect taxes — Indirect taxes are taxes on the sale of goods and services.

They are called 'indirect' because they are largely paid by consumers through higher prices, but collected by firms who then pay the government. Examples include VAT and GST. They are often regressive. When you buy a soft drink with a sales tax, you pay the tax indirectly through the price, and the shop collects it for the government.

ad valorem taxes — Ad valorem taxes are taxes based on the percentage of the price of a product.

This means the tax amount increases as the price of the product increases. VAT and GST are common examples of ad valorem taxes. They are a percentage of the value. If a tax is 10% of the price, a $10itemhasa$1 tax, and a $100itemhasa$10 tax – the tax amount changes with the value.

excise duties — Indirect taxes on particular products are sometimes known as excise duties.

These are specific taxes often levied on goods like tobacco, alcohol, or fuel. They can be used to raise revenue or to discourage consumption of certain products (sin taxes). The extra tax you pay on a pack of cigarettes or a litre of petrol is an excise duty.

sin taxes — Sin taxes are imposed to discourage people from buying products that are not good for their health.

These are a type of excise duty specifically targeting demerit goods like high-sugar drinks, tobacco, or high-fat foods. They aim to internalise negative externalities and improve public health. The tax on sugary drinks in Mexico is a sin tax, aiming to make people buy fewer unhealthy beverages.

progressive tax — A progressive tax is one that takes a higher percentage of a person or firm’s income as that income rises.

This type of tax aims to redistribute income more evenly, as those with higher incomes contribute a proportionally larger share. Income tax systems are often designed to be progressive. Imagine a ladder where each rung you climb (higher income) means a larger slice of that rung is taken as tax.

regressive tax — In the case of a regressive tax, a smaller percentage of income is taken as income rises.

This means that such a tax takes a higher percentage of the income of people on low incomes. Indirect taxes are typically regressive because the tax amount is fixed regardless of income, representing a larger proportion of a lower income. If everyone pays a $1taxonbread,that$1 is a much larger portion of a poor person's income than a rich person's income.

proportional tax — A proportional tax is a fixed percentage tax, for example a 20% income tax.

The tax rate does not change as income changes, meaning everyone pays the same percentage of their income in tax, regardless of their income level. This is also known as a flat rate tax. No matter how much you earn, if the tax is 15%, you always pay 15% of your income.

marginal rate of taxation (mrt) — The marginal rate of taxation (mrt) is the proportion of extra income taken in tax.

It indicates how much of an additional unit of income (e.g., an extra £100) is paid in tax. This rate is crucial for understanding work incentives, as it shows the tax burden on additional earnings. If you work an extra hour and earn £10, and £3 of that goes to tax, your marginal tax rate for that extra hour is 30%.

average rate of taxation (art) — The average rate of taxation (art) is the proportion of a person’s total income that is taken in tax.

It is calculated by dividing total tax paid by total income. This rate provides an overall picture of the tax burden on an individual's entire income. If you earn £50,000 in a year and pay £10,000 in tax, your average tax rate is 20% for that year.

Current government spending — Current government spending is spending on goods and services used to provide state-financed services.

This covers the operating costs of government, such as wages for public sector workers (teachers, doctors) and the purchase of consumables (medicines, office supplies). It is exhaustive spending and contributes to aggregate demand. This is like your household's monthly expenses for groceries, utilities, and salaries for any staff you employ.

Capital government spending — Capital government spending is spending on capital goods used in the public sector.

This includes investment in long-term assets like building state schools, hospitals, roads, and infrastructure. It is exhaustive spending, contributes to aggregate demand, and can increase an economy's productive potential (aggregate supply). This is like your household buying a new house or a car – a large, long-term investment.

transfer payments — Government spending on transfer payments (welfare payments to certain groups of people) includes spending on unemployment benefits, state pensions and interest payments on the national debt.

These payments do not involve the government directly purchasing goods or services or using resources; instead, they redistribute income. They are not counted in measures of national income (GDP) as they don't represent production. It's like your parents giving you pocket money – they're transferring money to you, but not buying a specific good or service from you.

Exhaustive government spending — Exhaustive government spending covers current and capital spending.

It is spending which uses resources and is counted in aggregate demand and GDP. This type of spending directly consumes goods and services produced in the economy. When the government buys new fighter jets or pays teachers' salaries, it's 'exhausting' resources from the economy.

Non-exhaustive government spending — Non-exhaustive government spending is spending on transfer payments.

This spending does not involve the government deciding how resources are used; instead, the people who receive the payments make the decision about how to use the resources. It is not counted in GDP. When the government sends out unemployment benefits, it's not buying anything itself; it's giving money to individuals who then decide how to spend it.

Expansionary fiscal policy — Expansionary fiscal policy is designed to increase aggregate demand.

This can be achieved by a government increasing its spending and/or cutting tax rates or the tax base. It is typically used to stimulate economic growth, reduce unemployment, and combat recessions, often leading to a larger budget deficit. It's like pressing the accelerator in a car to speed up the economy, by either giving people more money to spend (tax cuts) or the government spending more directly.

Contractionary fiscal policy — Contractionary fiscal policy is intended to lower the growth of aggregate demand.

This is achieved by the government reducing its spending and/or increasing taxes, often aiming for a budget surplus. It is typically used to reduce demand-pull inflation or to reduce a large national debt. It's like pressing the brake pedal in a car to slow down an overheating economy, by either taking money out of people's hands (tax increases) or the government spending less.

discretionary fiscal policy — Deliberate changes in government spending and taxation can be referred to as discretionary fiscal policy.

These are active policy decisions made by the government, such as passing new laws to change tax rates or approving new spending programs, in contrast to automatic stabilisers. This is like you consciously deciding to spend more on a holiday or save more for a house, rather than your spending changing automatically due to a pay rise.

Automatic stabilisers — Automatic stabilisers are forms of government spending and taxation that change, without any deliberate government action, to offset fluctuations (changes) in GDP.

During a recession, unemployment benefits automatically rise and tax revenues automatically fall, providing a fiscal stimulus. During a boom, the reverse happens, dampening demand. They help to smooth out the business cycle. Think of them as the cruise control in a car: they automatically adjust the engine (economy) to maintain a steady speed (GDP) without you having to constantly press the accelerator or brake.

Monetary policy — Monetary policy refers to any policy tools that affect the price or quantity of money.

It is a demand-side policy, similar to fiscal policy, aiming to influence aggregate demand. These tools are typically implemented by a country's central bank to achieve macroeconomic objectives like price stability or economic growth, much like adjusting a thermostat to control the temperature of a room.

Interest rates — The interest rate is, in effect, the price of money.

It is the cost households and firms pay to borrow money and the return they receive for lending or saving money. Central banks manipulate this rate to influence borrowing, saving, investment, and ultimately aggregate demand, similar to how 'rent' for money affects demand for borrowing.

Money supply — The money supply refers to the total quantity of money in the economy.

A central bank can influence the money supply, primarily by affecting commercial bank lending, which is the main cause of changes in the quantity of money. Changes in the money supply can directly influence aggregate demand, much like the amount of fuel available in an engine affects its speed.

Credit regulations — Credit regulations are rules imposed by central banks on commercial banks to help maintain financial stability and influence bank lending.

These regulations often require commercial banks to hold a certain proportion of their assets in liquid forms, ensuring they can meet customer demand for cash and influencing their capacity to lend. This affects the money supply and aggregate demand, acting like safety rules or speed limits for banks.

Aggregate demand — Aggregate demand refers to the total demand for goods and services in an economy at a given price level and in a given time period.

Monetary policy directly influences aggregate demand by affecting components like consumer expenditure and investment through changes in interest rates, money supply, and credit availability. It's like trying to make a country's total shopping list longer or shorter.

Expansionary monetary policy — Expansionary monetary policy may be used to increase aggregate demand.

This typically involves a cut in interest rates, an increase in the money supply, or a reduction in restrictions on bank lending. The goal is to stimulate consumer expenditure and investment, leading to higher national income, output, and employment, much like giving a sluggish economy a 'shot of espresso'.

Contractionary monetary policy — To reduce aggregate demand or the growth of AD, contractionary monetary policy may be used.

This might include a rise in interest rates, a decrease in the money supply, and restrictions on bank lending. It is often used to combat demand-pull inflation by discouraging borrowing and spending, akin to applying the 'brakes' to an overheating economy.

Price level — The price level refers to the average of current prices across the entire spectrum of goods and services produced in an economy.

Monetary policy is often primarily used to influence the price level, particularly to control inflation. Contractionary policy aims to reduce demand-pull inflation, while expansionary policy can lead to a higher price level if there is little spare capacity, much like trying to keep the overall 'cost of living' stable.

Real output — Real output refers to the total value of goods and services produced in an economy, adjusted for inflation.

Expansionary monetary policy aims to increase real output by stimulating aggregate demand, especially when there is spare capacity. Contractionary policy, while reducing inflation, may risk reducing real output if not carefully implemented, similar to getting a factory to produce more when it's underperforming.

Employment — Employment refers to the state of having paid work.

Expansionary monetary policy, by increasing aggregate demand and real output, is likely to lead to an in-crease in employment as firms hire more workers to produce additional goods and services. Contractionary policy, conversely, may have an adverse effect on employment, much like more roles opening up in a growing company.

Supply-side policy — Governments use supply-side policies to increase aggregate supply by improving the workings of product and factor markets.

These policies aim to increase the economy's productive capacity, shifting the long-run aggregate supply (LRAS) curve to the right. They can involve either increased government intervention, such as spending on education, or reduced intervention, such as deregulation, much like upgrading a restaurant kitchen to produce more meals.

Productivity — Productivity is the measure of output generated from inputs, where an increase means more goods and services can be produced with the same sized labour force.

Increasing productivity is the main way supply-side tools try to increase productive capacity. For example, improved training can raise workers' skills and thus their productivity, similar to a student learning to write a longer essay in the same time.

Productive capacity — Productive capacity is the potential output of an economy, which supply-side policies seek to increase, thereby shifting the long-run aggregate supply (LRAS) curve to the right.

An increase in a country's productive capacity is a key objective of supply-side policy, achieved by increasing the quality and quantity of resources, such as a better-educated labour force or more advanced capital equipment. This is like a factory adding a new production line to increase its maximum daily output.

Infrastructure — Infrastructure includes efficient transport, power, energy and telecommunication networks that are essential for the economy.

Good quality infrastructure keeps the costs of firms low and enables them to get their products to market quickly, much like a good operating system allows computer software to run smoothly. For example, an improved rail network reduces transport costs and makes workers more punctual.

Privatisation — Privatisation is the process of transferring firms from public sector ownership to the private sector, which many countries have adopted in the belief that firms operate more efficiently in the private sector.

As a supply-side tool, privatisation is intended to increase efficiency, which in turn can increase aggregate supply, similar to a city council selling its bus service to a private company expecting more efficient operation. It is often paired with deregulation to promote competition.

Deregulation — Deregulation involves removing barriers to entry and laws and regulations that increase firms’ costs of production.

This supply-side tool is used to make markets more competitive and efficient by reducing legal and administrative burdens on businesses, aiming to lower production costs and encourage new firms to enter the market, thereby increasing aggregate supply. This is like removing rules in a board game to make it faster and easier for new players to join.

Absolute advantage — A country has an absolute advantage in producing a product if it can produce more of the product with the same quantity of resources than another country.

This theory suggests that countries should specialise in producing goods where they are simply more efficient, meaning they can produce more with the same resources than other countries. For example, if one friend can bake 10 cakes in an hour while another bakes 5, the first friend has an absolute advantage in baking. Specialisation and trade based on absolute advantage can increase total output and allow both countries to consume more.

Comparative advantage — A country has a comparative advantage in producing a product if it can produce that product at a lower opportunity cost than another country.

This theory explains why countries still benefit from trade even if one country has an absolute advantage in all products. It focuses on the relative efficiency and the trade-offs involved in production, leading to specialisation in the product with the lowest opportunity cost. For instance, a lawyer might be better at both law and typing than their assistant, but the assistant has a comparative advantage in typing because the opportunity cost of the lawyer typing (lost billable hours) is much higher.

Trading possibility curve — A trading possibility curve shows how an economy can benefit from specialising and trading, enabling it to consume a greater quantity of products than it could produce domestically.

This curve illustrates that while a country cannot produce outside its Production Possibility Curve (PPC), international trade allows it to consume beyond its PPC. By specialising in its comparative advantage and trading, a country can achieve a higher level of consumption. For example, a gardener specialising in tomatoes can trade some for a neighbour's cucumbers, enjoying more of both than if they tried to grow both themselves.

Terms of trade — The terms of trade is a measure of the ratio of a country's index of export prices to its index of import prices, multiplied by 100.

It indicates how many imports a country can purchase with a given quantity of exports. An improvement (favourable movement) means fewer exports are needed to buy the same imports, while a deterioration (unfavourable movement) means more exports are needed. Imagine selling apples and buying oranges; if the price of your apples goes up relative to oranges, you can buy more oranges for the same number of apples, indicating improved terms of trade.

Prebisch-Singer hypothesis — The Prebisch-Singer hypothesis suggests that the terms of trade tend to move against countries that produce primary products.

This hypothesis is based on the view that as global incomes rise, the demand for manufactured goods and services increases proportionally more than the demand for primary products. This can lead to a long-term decline in the relative prices of primary products compared to manufactured goods. For example, a farmer selling raw ingredients might see their prices rise slower than a chef selling gourmet meals as people get richer.

Protectionism — Protectionism is when governments seek to protect domestic industries from foreign competition.

It involves the restriction of free trade, often aiming to increase the price competitiveness of domestic industries. This can be achieved through various tools that make imported goods more expensive or less available, much like a parent limiting a child's exposure to competitive sports until they are confident.

Tariffs — Tariffs are taxes, usually on imports but they may also be imposed on exports.

Also known as customs duties, tariffs can be specific (a fixed sum per unit) or ad valorem (a percentage of the price). They increase the cost of imported goods, making domestic products more competitive or raising government revenue, similar to an extra toll on foreign goods entering a country.

Quotas — Quotas are limits on imports, usually imposed on the quantity of imports.

By restricting the supply of imports, quotas tend to drive up their price, disadvantaging consumers through higher prices and reduced product availability. Unlike tariffs, quotas typically do not generate revenue for the government, unless licences are sold, much like a bouncer limiting the number of people entering a club.

Subsidies — Subsidies may be given to both exporters and to those domestic firms that compete with imports.

These payments effectively reduce the costs for domestic firms, encouraging them to increase output and lower prices. This can help them gain market share at home and abroad, but at the expense of foreign firms and domestic taxpayers, similar to a coach giving extra training and equipment to a specific player.

Embargo — An embargo is a complete ban either on the imports of a particular product or on trade with a particular country.

Governments may impose embargoes on products deemed harmful (e.g., non-prescription drugs, weapons) or on trade with specific countries due to political disputes. It is the most extreme form of trade restriction, akin to a complete lockdown of a city.

Voluntary export restraints — Voluntary export restraints are an agreement by an exporting country to restrict the amount of a product that it sells to the importing country.

Also called voluntary export restrictions, these agreements are often a result of pressure from the importing country or a reciprocal agreement to limit other exports. They function similarly to quotas but are initiated by the exporting country, like friends agreeing to limit items brought to a party.

Excessive administrative burdens — Excessive administrative burdens, or 'red tape', involve requiring importers to fill out lengthy forms that are time-consuming to complete.

Governments may also set artificially high product standards to restrict foreign competition. These measures discourage imports by increasing the non-price costs and complexities for foreign firms, thereby restricting consumer choice, much like complex permit processes for a simple home renovation.

Exchange control — Exchange control is when a government places limits on the amount of foreign exchange that can be purchased in order to buy imports, travel abroad or invest abroad.

Instead of directly limiting imports, this tool restricts the financial means available to purchase them. By controlling access to foreign currency, a government can indirectly reduce import demand, similar to a parent giving a child a limited allowance specifically for toys.

Dumping — Dumping involves selling products at below their cost price.

This practice is often regarded as unfair competition. While home consumers may benefit in the short run from lower prices, in the long run, foreign firms engaging in dumping may drive out domestic firms, gain a monopoly, and then raise prices, much like a supermarket selling below cost to eliminate competition.

Infant industries — Infant industries are firms in a new industry that may find it difficult to survive when faced with competition from more established, larger foreign firms.

Protection is given to these 'sunrise' industries to allow them time to grow, benefit from economies of scale, and gain an international reputation. The justification is that they have the potential to develop into efficient industries with a comparative advantage, much like a newborn baby needing protection to grow strong.

Declining industries — Declining industries, also called sunset industries, are those that have lost their comparative advantage.

Protection may be given to these industries to prevent a sudden and large rise in unemployment if they go out of business quickly. Gradual removal of protection allows workers to retire or move to other industries, easing the transition, similar to a person gradually reducing work hours before retirement.

Strategic industries — Strategic industries are those that produce products regarded as essential, such as weapons, fuel, and food.

Governments may protect these industries to avoid dependence on foreign supplies, especially in times of trade disputes or military conflict. This ensures national security and stability, even if the domestic industries are relatively inefficient, much like a country ensuring it has its own military.

balance of payments — A country’s balance of payments is a record of all the economic transactions between residents of that country and residents in other countries.

This comprehensive record tracks all money flowing into and out of a country from international activities, much like a household's bank statement. It encompasses the current account, capital account, and financial account, with money flowing in creating credit items and money flowing out creating debit items.

Trade in goods — Trade in goods refers to the exports and imports of goods such as cars, TVs and clothing.

This component, also known as the 'visible balance' or 'merchandise balance', tracks the buying and selling of physical products internationally. Exports generate credit items (money coming in), while imports generate debit items (money going out), with the balance calculated as export revenue minus import expenditure.

Trade in services — Trade in services refers to the trade in exports and imports of services, which may be referred to as ‘invisibles’.

This includes services like shipping, tourism, banking, and insurance. A country earns money from foreign tourists (exporting services) but spends money on foreign travel agencies for its own citizens' holidays (importing services). A deficit occurs when revenue from service exports is less than expenditure on service imports.

Primary income — Primary income includes income in the form of profits, interest and dividends earned on direct investment abroad and foreign earnings on investment in the country.

This is like a country's investment portfolio, tracking the income generated from existing investments and labour across borders. It includes profits, interest, and dividends from investments, as well as wages earned by a country's residents working abroad (employees’ compensation).

Secondary income — Secondary income includes payments made and receipts received for which there is no corresponding exchange of an actual good or service.

This category covers unilateral transfers, like sending a gift or charity donation internationally, where money moves without a direct quid pro quo. Examples include government transfers such as foreign aid and payments to international organisations, as well as private transfers like workers’ remittances sent home by people working abroad.

current account deficit — A current account deficit means that the combined debit items on the four parts of the current account balance are greater than the combined credit items on the four parts.

This implies a country is spending more on international transactions (imports, income outflows, transfers) than it is earning (exports, income inflows, transfers). Like a person spending more than they earn, it must be financed by attracting investment or borrowing from abroad.

current account surplus — A current account surplus occurs when the credit items on the four parts are greater than the combined debit items.

This means a country is earning more from international transactions than it is spending. While it allows for the accumulation of foreign assets, it can also indicate that residents are not enjoying as high a standard of living as possible or lead to inflationary pressure domestically.

cyclical deficit — A current account deficit that arises from either change in the economic cycle of the domestic economy or the economies of trading partners is sometimes referred to as a cyclical deficit.

This type of deficit is usually not considered a major problem as it is likely to be relatively short-term and self-correcting. For instance, a rapidly growing domestic economy might temporarily increase imports of raw materials and consumer goods, leading to a deficit that corrects as the growth rate stabilises.

structural deficit — A current account deficit that lasts over the long run is more of a concern.

This indicates that domestic firms are not internationally competitive, possibly due to an overvalued exchange rate, high inflation, low labour/capital productivity, poor education, or insufficient investment and innovation. Unlike cyclical deficits, structural deficits are not self-correcting and require policy intervention.

Foreign exchange rate — The foreign exchange rate is the price of one currency in terms of another currency.

It shows the external value of a currency, indicating how much of a foreign currency can be bought with a unit of the domestic currency, or vice versa. Changes in this rate affect the relative prices of exports and imports, much like the price of an apple in terms of oranges.

Floating exchange rate — A floating exchange rate is one determined by market forces.

This means the value of the currency is set by the interaction of demand for and supply of that currency on the foreign exchange market, without direct government intervention to fix its price. Its value can fluctuate freely, similar to the price of a popular toy determined solely by demand and supply.

Depreciation — A fall in the value of a currency caused by market forces is known as a depreciation.

This means that more units of the domestic currency are needed to buy one unit of a foreign currency. It makes exports cheaper for foreigners and imports more expensive for domestic consumers, much like your local currency buying less US dollars than before.

Appreciation — A rise in the value of the currency, caused by an increase in demand and/or a decrease in supply, is known as an appreciation.

This means fewer units of the domestic currency are needed to buy one unit of a foreign currency. It makes exports more expensive for foreigners and imports cheaper for domestic consumers, similar to your local currency buying more US dollars than before.

Hot money flows — Short-term movements of money between countries seeking to gain a financial advantage by earning higher interest rates and buying currencies that are expected to rise in prices are sometimes referred to as hot money flows.

These flows are highly sensitive to interest rate differentials and exchange rate expectations, moving quickly between financial centres. They can cause significant fluctuations in a country's exchange rate, much like investors quickly moving funds to where they can find the highest returns.

National income — National income refers to the total income earned by a country's factors of production.

In the context of exchange rates, a depreciation can increase net exports, leading to higher aggregate demand and thus a rise in national income, similar to a country's overall 'paycheck' growing when more goods are sold abroad.

Real output — Real output refers to the total volume of goods and services produced in an economy, adjusted for inflation.

A depreciation can stimulate aggregate demand, leading to an increase in real output as firms produce more to meet higher demand. An appreciation can lead to a fall in real output, much like counting the actual number of goods produced rather than just their monetary value.

Price level — The price level is the average of current prices across the entire spectrum of goods and services produced in an economy.

A depreciation can lead to a rise in the domestic price level due to increased aggregate demand, more expensive imports, and higher costs of imported raw materials. An appreciation can reduce inflationary pressure, similar to the total cost of a giant shopping basket of goods.

Aggregate demand — Aggregate demand is the total demand for goods and services in an economy at a given price level and in a given time period.

A depreciation increases net exports, which is a component of aggregate demand, thus shifting the AD curve to the right. An appreciation reduces net exports, shifting the AD curve to the left, representing the total spending power of everyone in the country.

Aggregate supply — Aggregate supply is the total supply of goods and services produced within an economy at a given overall price level in a given time period.

An appreciation can shift the aggregate supply curve to the right by reducing the cost of imported raw materials, leading to lower production costs for domestic firms. A depreciation would have the opposite effect, representing the total amount of goods and services businesses are willing to produce.

Current Account Deficit — A situation where more is spent on imports than earned from exports.

A current account deficit means a country is consuming more goods and services than it produces, with money leaving the country exceeding money entering. While it can allow for higher consumption and the import of productive capital goods in the short run, like a household consistently spending more than its income, it can lead to international debt if persistent.

Current Account Surplus — A situation where there is a surplus of export revenue over import expenditure.

A current account surplus occurs when a country earns more from its exports than it spends on imports. This can boost aggregate demand and provide funds to repay external debt. However, like an individual earning a high salary but saving almost all of it, it also means the country is giving up the opportunity to buy foreign products it can afford.

Contractionary Fiscal Policy — A policy involving increasing income tax and reducing government spending to reduce demand for goods and services, including imports.

This policy addresses a current account deficit by reducing households' disposable income through higher income tax, leaving less money for imports. Lower government spending directly cuts overall demand, which can also reduce imports and encourage domestic firms to seek export markets. It's like a family cutting spending to reduce debt, lowering their standard of living in the short term.

Supply-side Policy — Policies that aim to increase the quantity and quality of a country's resources to make domestic products more competitive.

These policies are a long-term strategy to correct a current account deficit by tackling structural weaknesses. Measures like deregulation, privatisation, spending on education and training, and trade union reform can increase efficiency, lower costs, and improve product quality. This makes domestic goods more attractive both at home and abroad, increasing exports and reducing import dependency, much like investing in education to improve long-term earning power.

Protectionist Policy — A policy, such as imposing a tariff, used as a way of encouraging domestic consumers and firms to switch to buying domestic products.

This policy directly targets imports to reduce a current account deficit. By imposing a tariff (a tax on imports), the government makes foreign goods more expensive, hoping consumers will buy cheaper, domestically produced substitutes instead. This is like a school cafeteria raising the price of outside snacks to encourage buying in-house.

Utility — Utility is a measure of the level of happiness or satisfaction that someone receives from the consumption of a good.

Economists use utility to quantify satisfaction, assuming it can be measured in units. This concept helps explain why consumers are willing to pay different amounts for successive units of a good, as their satisfaction changes. For example, the first time you hear your favourite song, you get immense satisfaction (high utility), but the tenth time in a row, the additional satisfaction might be less.

total utility — Total utility is the overall satisfaction that is derived from the consumption of all units of a good over a given time period.

It is the sum of all marginal utilities from consuming each unit of a good. As consumption increases, total utility generally rises, but at a decreasing rate due to diminishing marginal utility. For instance, if you eat three slices of pizza, your total utility is the combined satisfaction from all three slices.

marginal utility — Marginal utility is the additional utility derived from the consumption of one more unit of a particular good.

It is the change in total utility resulting from consuming one extra unit. The law of diminishing marginal utility states that this additional satisfaction tends to decrease as more units are consumed. If your first slice of pizza gives you 10 units of satisfaction and your second gives you 5 units, the marginal utility of the second slice is 5 units.

diminishing marginal utility — The law of diminishing marginal utility suggests that as consumption of a good increases, the marginal utility will get smaller.

This principle explains why consumers are willing to pay less for successive units of a good. The satisfaction gained from each additional unit decreases, even if total satisfaction is still rising. For example, after a long run, your first glass of water is incredibly satisfying, but subsequent glasses provide less additional satisfaction.

equi-marginal principle — The equi-marginal principle states that a consumer is in equilibrium when it is not possible to switch any expenditure from one product to another to increase total utility.

This occurs when the ratio of marginal utility to price (MU/P) is equal for all goods consumed. It ensures that the last dollar spent on each good yields the same amount of additional satisfaction, thus maximising total utility. Imagine you have a budget for snacks; you'll keep buying different snacks until the 'satisfaction per dollar' is the same for the last unit of each snack.

individual demand curve — An individual demand curve shows the quantity of a good that a single consumer is willing and able to purchase at different prices over a given period.

It can be derived from marginal utility theory by showing how a consumer's utility-maximising quantity demanded changes as the price of a good changes, assuming other factors remain constant. If the price of your favourite coffee drops, you might buy more cups because the satisfaction per dollar spent has increased, leading to a new utility-maximising point.

indifference curve — An indifference curve shows all of the combinations of two goods that give the consumer equal satisfaction or utility.

These curves are downward-sloping and convex to the origin, reflecting the marginal rate of substitution. Higher indifference curves represent higher levels of satisfaction, which rational consumers always prefer. Imagine choosing between pizza slices and soda cans; an indifference curve shows all combinations that make you equally happy.

indifference map — An indifference map is a diagram showing a number of different indifference curves.

It illustrates multiple levels of satisfaction, with curves further from the origin representing higher utility. Rational consumers aim to reach the highest possible indifference curve given their budget. Think of a contour map showing different altitudes on a mountain; each contour line represents a specific height, just as each indifference curve represents a specific level of satisfaction.

marginal rate of substitution — The rate at which the consumer is willing to substitute one good for another in this way is known as the marginal rate of substitution.

It is represented by the slope of the indifference curve. As a consumer has more of one good, they are willing to give up less of the other good to obtain an additional unit of the first, leading to the convex shape. For example, if you have a lot of chocolate and very little fruit, you might be willing to give up a lot of chocolate for just one more piece of fruit.

budget line — A budget line shows numerically all the possible combinations of two goods that a consumer can purchase with a given income and given prices of the two goods.

It represents the consumer's budget constraint, illustrating the trade-offs between two goods given their income and prices. Any point on or below the line is affordable, while points above are not. Imagine you have $100tospendonapples($1 each) and bananas ($2 each); the budget line shows all the combinations you can buy.

substitution effect — As the price of X has fallen relative to that of Y, which is unchanged, consumers will substitute X for Y. This is known as the substitution effect of a price change.

It is the change in consumption of a good due to a change in its relative price, holding real income constant. Consumers always substitute towards the relatively cheaper good. For example, if the price of coffee drops but tea stays the same, you might buy more coffee and less tea, substituting the cheaper coffee.

income effect — With the fall in the price of X, the consumer actually has more money to spend on other goods, X included. Real income has therefore increased, which may mean that a consumer may now purchase even more of good X. This is called the income effect of a price change.

It is the change in consumption of a good due to a change in real income resulting from a price change, holding relative prices constant. The income effect can be positive (normal goods) or negative (inferior/Giffen goods). If the price of your favourite snack drops, it's like having extra money, which you might use to buy more of that snack or other items.

Giffen good — A Giffen good is one where if the price of the good falls, demand falls and demand increases as the price increases.

This is an unusual type of inferior good where the negative income effect is so strong that it outweighs the positive substitution effect. For low-income families, this could be a staple food where a price fall frees up income to buy more preferred, expensive goods, reducing demand for the staple. Imagine a very poor family whose main food is cheap rice; if the price of rice falls, they might buy less rice to afford other goods.

Productive efficiency — Productive efficiency occurs when firms produce at the lowest possible cost, making the best use of resources.

This means that for a given set of inputs, the maximum possible output is produced, or a given output is produced with the minimum possible resources. In a competitive market, firms are incentivised to achieve productive efficiency to maximise profits or avoid bankruptcy. Imagine a baker who can make the most number of loaves of bread using the least amount of flour, yeast, and oven time compared to any other baker; this baker is productively efficient.

Allocative efficiency — Allocative efficiency occurs when firms produce the combination of goods and services that are most wanted by consumers, giving them maximum satisfaction.

This state is achieved when the price consumers are willing to pay for a good equals its marginal cost of production (P=MC). This ensures that resources are allocated to produce precisely the right amount of each product, reflecting consumer preferences and the true economic cost. Think of a restaurant that perfectly matches its menu to what its customers truly desire, at prices that reflect the cost of making each dish; no food is wasted, and customers are perfectly satisfied.

Pareto optimality — Pareto optimality occurs when it is impossible to make someone better off without making someone else worse off.

This represents the best possible situation in the circumstances, with resources allocated in the most efficient way. If an allocation is not Pareto efficient, there is an opportunity for a Pareto improvement, where at least one person can be made better off without harming anyone else. Imagine a group of friends sharing a pizza; if the pizza is divided so that no one can get a bigger slice without someone else getting a smaller slice, that's Pareto optimal.

Dynamic efficiency — Dynamic efficiency is a form of productive efficiency that benefits a firm over time, achieved when resources are reallocated to increase output relative to resource increase, meeting changing market needs through new production processes.

This involves investment in research, development, and innovation, often funded by excess profits, to protect market share and improve production methods. It is a long-run concept that leads to a downward shift in the long-run average cost curve, benefiting consumers through new technologies and lower prices. Consider a smartphone company that constantly invests in R&D to develop new, more powerful, and cheaper-to-produce phone models; this continuous improvement makes them dynamically efficient.

Market failure — Market failure exists whenever a free market, left to its own devices and totally free from any form of government intervention, fails to make the best use of scarce resources.

This occurs when the interaction of supply and demand does not lead to productive and/or allocative efficiency, resulting in an inefficient allocation of resources. Examples include externalities, public goods, information failure, and abuse of monopoly power. Imagine a traffic light system that malfunctions, causing chaos and accidents instead of smooth traffic flow; the market, like the traffic light, fails to coordinate resources efficiently.

Private costs (PC) — Private costs are the costs incurred by firms, individuals or others who actually carry out the particular action, either as producers or consumers.

These are the direct costs borne by the economic agent making the decision. For a producer, this includes production expenses like wages and raw materials; for a consumer, it's the price paid for a good or service. For example, the private cost of driving a car is the fuel you buy and the maintenance you pay for.

Private benefits (PB) — Private benefits are directly received by those who produce or consume the good or service in the action.

These are the direct advantages or utility gained by the economic agent making the decision. For a producer, this is revenue; for a consumer, it's the satisfaction or utility from consuming a good. For instance, the private benefit of eating a meal is the satisfaction of hunger and enjoyment of the food.

Externality — An externality is the effect, negative or positive, on a so-called third party who has had no involvement in the action that has caused the externality.

Externalities arise when economic decisions by producers or consumers affect third parties not directly involved in the transaction. These side effects can be either beneficial or detrimental, leading to a divergence between private and social costs or benefits and thus market failure. Imagine your neighbour decides to host a loud party every weekend. The noise is an externality; it's a negative effect on you (a third party) from their decision to party, even though you're not involved in their party planning or attendance.

External costs (EC) — External costs are a consequence of externalities that arise from a particular action and are not paid for by those responsible for the action, instead falling on third parties.

These are the uncompensated costs imposed on third parties due to the production or consumption activities of others. They represent a negative spillover effect, leading to social costs being higher than private costs. For example, the external cost of a factory polluting a river is the cost to local residents who can no longer fish or swim, or the cost to the public health system for treating pollution-related illnesses.

External benefits (EB) — External benefits are a consequence of externalities that arise from a particular action and whose advantages do not accrue to those responsible for the action, instead falling on third parties.

These are the uncompensated benefits received by third parties due to the production or consumption activities of others. They represent a positive spillover effect, leading to social benefits being higher than private benefits. For instance, the external benefit of someone getting vaccinated is that others in the community are less likely to catch the disease from them, even if they weren't vaccinated themselves.

Social costs (SC) — Social costs are the total costs incurred or accruing to society as a result of a particular action.

Social costs encompass both the private costs borne by the decision-maker and any external costs imposed on third parties. They represent the true cost to society of an economic activity. The social cost of driving a car includes your fuel costs (private cost) plus the cost of air pollution and road congestion imposed on others (external costs).

Social benefits (SB) — Social benefits are the total benefits incurred or accruing to society as a result of a particular action.

Social benefits encompass both the private benefits received by the decision-maker and any external benefits enjoyed by third parties. They represent the true benefit to society of an economic activity. The social benefit of getting an education includes your increased earning potential (private benefit) plus the benefits to society of a more skilled workforce and informed citizenry (external benefits).

Negative externality — A negative externality occurs where the side effects have a negative or damaging impact on third parties involving unexpected costs to them.

These externalities impose uncompensated costs on individuals or groups not directly involved in the production or consumption of a good or service. They lead to social costs exceeding private costs, resulting in overproduction or overconsumption from society's perspective. A factory polluting a river is a negative externality; the factory benefits from cheaper waste disposal, but local fishermen (third parties) incur costs from reduced fish stocks.

Positive externality — A positive externality is where the side effects provide unexpected benefits to the third parties.

These externalities generate uncompensated benefits for individuals or groups not directly involved in the production or consumption. They lead to social benefits exceeding private benefits, resulting in underproduction or underconsumption from society's perspective. If your neighbour plants a beautiful garden, you (a third party) benefit from the pleasant view and improved air quality without paying for it; this is a positive externality.

Marginal private costs (MPC) — Marginal private costs are the costs incurred by the firm for producing one additional unit of a good or service.

This is essentially the firm's supply curve, representing the additional cost to the producer for each extra unit. In the absence of externalities, MPC equals Marginal Social Cost. For a baker, the MPC of baking one more loaf of bread is the cost of the extra flour, yeast, and energy used.

Marginal external costs (MEC) — Marginal external costs are the additional costs imposed on third parties by the production or consumption of one more unit of a good or service.

These costs are not borne by the producer or consumer but by society. They represent the vertical distance between the Marginal Private Cost (MPC) and Marginal Social Cost (MSC) curves in production externalities, or between Marginal Private Benefit (MPB) and Marginal Social Benefit (MSB) in consumption externalities. The MEC of a factory producing one more unit of a product might be the additional cost of treating one more person for respiratory illness due to increased air pollution.

Marginal social costs (MSC) — Marginal social costs are the total costs to society of producing one additional unit of a good or service.

MSC includes both the marginal private cost and any marginal external cost. When MSC is greater than MPC, it indicates a negative production externality, leading to overproduction from society's perspective. The MSC of producing one more car includes the cost to the car manufacturer (MPC) plus the cost of the extra pollution emitted to the environment (MEC).

Marginal private benefit (MPB) — Marginal private benefit is the additional benefit received by the consumer from consuming one more unit of a good or service.

This is typically represented by the demand curve, reflecting the utility or satisfaction an individual gains from an extra unit. In the absence of externalities, MPB equals Marginal Social Benefit. The MPB of eating one more slice of pizza is the additional satisfaction you get from that slice.

Marginal external benefit (MEB) — Marginal external benefit is the additional benefit received by third parties from the production or consumption of one more unit of a good or service.

These benefits are not captured by the producer or consumer but accrue to society. They represent the vertical distance between the Marginal Private Benefit (MPB) and Marginal Social Benefit (MSB) curves in consumption externalities, or between Marginal Private Cost (MPC) and Marginal Social Cost (MSC) in production externalities. The MEB of one more person getting educated might be the additional benefit to society from a more informed voter or a more productive worker.

Marginal social benefit (MSB) — Marginal social benefit is the total benefit to society from consuming one additional unit of a good or service.

MSB includes both the marginal private benefit and any marginal external benefit. When MSB is greater than MPB, it indicates a positive consumption externality, leading to underconsumption from society's perspective. The MSB of one more person getting vaccinated includes the benefit to that individual (MPB) plus the benefit to the community from reduced disease transmission (MEB).

deadweight welfare loss — Deadweight welfare loss is the loss of economic efficiency that can occur when the free market equilibrium for a good or service is not achieved or is not socially optimal.

This loss represents the reduction in total surplus (consumer and producer surplus) that results from underproduction or overproduction relative to the socially efficient level. It is typically shown as a triangular area on a supply and demand diagram. Imagine a cake that could feed 10 people perfectly, but due to a miscalculation, only enough is baked for 8, or enough for 12 but 2 slices go to waste. The 'missing' or 'wasted' slices represent the deadweight welfare loss.

Asymmetric information — Asymmetric information occurs when one party in the market, usually the seller, has some information that the other party, usually the buyer, does not have.

This imbalance of information can lead to market failure because the party with less information may make suboptimal decisions, or the market for certain goods may collapse due to adverse selection. When buying a used car, the seller knows its true condition (e.g., if it's a 'lemon'), but the buyer doesn't, leading to asymmetric information.

Adverse selection — Adverse selection is an outcome of hidden characteristics, where only one party knows more about a situation than the other party, leading to undesirable market outcomes.

This occurs before a transaction takes place, where one party has private information about a characteristic that is relevant to the transaction. For example, in insurance, unhealthy people are more likely to buy insurance, leading to higher costs for insurers. If only people with high risk of flooding buy flood insurance, the insurance company faces adverse selection because it attracts a disproportionately risky pool of customers.

Moral hazard — Moral hazard refers to situations involving hidden actions, where one party takes actions that the other party cannot observe but which affect both of them.

This occurs after a transaction, where one party changes their behaviour because they are protected from the full consequences of their actions. For example, an insured person might take more risks knowing their losses are covered. If you have comprehensive car insurance, you might drive less carefully (a hidden action) because the cost of an accident is largely covered, which is moral hazard.

cost–benefit analysis — Cost–benefit analysis is a useful technique to aid decision-making by analysing the various costs and benefits that are involved, particularly where a financial appraisal alone may not be entirely appropriate.

CBA takes a long and wide view, including all social costs and social benefits, not just private ones, and often assigns shadow prices to non-market costs and benefits. It is widely used in the public sector for major investment projects to determine if the overall benefits to society outweigh the costs. Deciding whether to build a new public park involves a CBA: you'd weigh the construction costs and maintenance (costs) against the benefits of recreation, improved air quality, and increased property values for nearby residents (benefits).

production function — The production function is a graph showing the relationship between the quantity of factor inputs (labour/workers) and the total product or output of clothing.

It illustrates how output changes as variable inputs are added to fixed inputs in the short run. This concept is fundamental to understanding productivity and the law of diminishing returns. For example, a baker with a fixed oven (capital) uses the production function to show how many loaves of bread they can bake as they add more bakers (labour) to operate that single oven.

marginal product — Marginal product is the increase in total product that occurs from an additional unit of input (labour, in this case).

It measures the extra output gained by employing one more unit of a variable factor, holding other factors constant. This concept is crucial for understanding the law of diminishing returns and a firm's short-run decision-making. For instance, if a team of workers picks apples, the marginal product of the fifth worker is the extra number of apples picked when that fifth worker joins the team, compared to what four workers picked.

average product — Average product is calculated by dividing the total product by the number of workers employed.

It is a measure of labour productivity, indicating how much output is produced by each worker on average. Firms use this to assess the overall efficiency of their workforce. For example, if a factory produces 100 cars with 10 workers, the average product is 10 cars per worker.

law of diminishing returns — The law of diminishing returns states that as the number of workers increases, the marginal product declines.

This short-run concept occurs when successive units of a variable input are added to a fixed input, eventually leading to a decrease in the marginal output of the variable input. It explains the U-shape of short-run cost curves. Imagine adding more and more fertiliser to a potted plant; initially, the plant grows faster, but eventually, adding more fertiliser might not help much, or could even harm the plant, showing diminishing returns.

Fixed costs (FC) — Fixed costs (FC) are the costs that are independent of output.

These costs do not change with the level of production in the short run, such as rent or insurance. They must be paid even if output is zero, and their total remains constant. The rent for a factory building is a fixed cost; whether the factory produces 100 units or 1000 units, the rent payment remains the same.

Variable costs (VC) — Variable costs (VC) include all the costs that are directly related to the level of output, the usual ones being labour and raw material or component costs.

These costs fluctuate with the volume of production; they are zero if no output is produced and increase as output increases. They are incurred directly in the production process. The cost of raw materials to make a product is a variable cost; if you make more products, you use more raw materials, and the cost increases.

total cost (TC) — Total cost (TC) is the sum of total fixed cost (TFC) and total variable cost (TVC).

It represents the overall cost of producing a given level of output. Understanding total cost is essential for firms to determine profitability and make production decisions. If your fixed costs for a lemonade stand are the cost of the stand itself, and your variable costs are the lemons and sugar, your total cost is the sum of these for all the lemonade you make.

average fixed cost (AFC) — Average fixed cost (AFC) is calculated by dividing total fixed cost by output.

AFC continuously falls as output increases because the total fixed cost is spread over a larger number of units. This contributes to the initial downward slope of the average total cost curve. If your factory rent is $1000andyouproduce100units,yourAFCis$10 per unit. If you produce 1000 units, your AFC drops to $1 per unit.

average variable cost (AVC) — Average variable cost (AVC) is calculated by dividing total variable cost by output.

AVC typically falls initially due to increasing returns, then rises due to the law of diminishing returns. It represents the variable cost incurred per unit of output. If the total cost of ingredients for 10 pizzas is $50,theAVCis$5 per pizza.

average total cost (ATC) — Average total cost (ATC) is calculated by dividing total cost by output.

Also known as unit cost, ATC shows the cost per unit of output. Its U-shape in the short run is due to the interaction of falling AFC and rising AVC. If the total cost to produce 100 toys is $500,theaveragetotalcostis$5 per toy.

Marginal cost (MC) — Marginal cost (MC) is the addition to the total cost when making one extra unit of output.

It is the change in total cost divided by the change in output. MC is crucial for firms' short-run output decisions, as they will only increase output if expected revenue outweighs this extra cost. If producing 10 shirts costs $100andproducing11shirtscosts$108, the marginal cost of the 11th shirt is $8.

optimum output — Optimum output is where the firm is productively efficient in the short run, meaning the average total or unit cost is lowest.

This is the level of output where the firm achieves the lowest possible cost per unit in the short run. It occurs at the minimum point of the average total cost curve, where MC = ATC. For a bakery, the optimum output is the number of loaves of bread they can bake where the cost per loaf is the absolute lowest, given their current oven and staff.

isoquant — An isoquant is a curve that joins points that give a particular level of output.

Isoquants illustrate different combinations of labour and capital that can produce the same quantity of output. They are used in long-run production analysis to show the physical relationship between inputs and output, distinct from cost considerations. Imagine you're baking a cake. An isoquant would show all the different combinations of flour and sugar that would still result in one perfectly sized cake, even if the taste varies slightly.

isocosts — Isocosts are lines of constant relative costs for the factors of production.

They represent all combinations of two inputs (e.g., labour and capital) that a firm can purchase for a given total cost. Firms combine isocosts with isoquants to find the least-cost production method. If you have a fixed budget for buying ingredients, an isocost line would show all the different combinations of flour and sugar you could buy with that exact amount of money.

expansion path — The expansion path or long-run production function of the firm can be shown by joining together all of the various tangential points between isoquants and isocosts.

It illustrates the least-cost combination of inputs for every possible level of output in the long run. This path is crucial for long-term planning as it shows how a firm should adjust its factor mix as it expands. Imagine a path on a map that shows the most efficient route to reach different destinations (output levels) while spending the least amount of fuel (cost).

long-run average cost (LRAC) — The long-run average cost (LRAC) curve shows the least cost combination of producing any given quantity of output.

It is a flatter U-shaped curve that envelops a series of short-run average cost curves, representing the lowest possible average cost for each output level when all factors of production are variable. Think of the LRAC as the 'best possible' average cost curve you could achieve if you could choose the perfect factory size (SRAC) for every level of output.

short-run average cost curve (SRAC) — The short-run average cost curve (SRAC) shows the average cost of production for a given plant size, where at least one factor of production is fixed.

Each SRAC curve represents the average costs for a specific scale of operation in the short run. The LRAC curve is derived from a series of these SRAC curves. If you have a small coffee shop, your SRAC curve shows your average costs for different numbers of coffees made with that specific shop size. If you build a bigger shop, you'd have a new SRAC curve.

minimum efficient scale — The minimum efficient scale is the lowest level of output where average costs are minimised.

At this point, a firm has maximised its efficiency in both the short and long run. Industries with a low minimum efficient scale tend to have many firms, while those with a high scale have fewer, larger firms. For a car manufacturer, the minimum efficient scale is the production volume where they achieve the lowest possible cost per car, fully utilising all economies of scale.

economies of scale — A firm experiences economies of scale if costs per unit of output fall as the scale of production increases.

These occur when a firm's output rises proportionally faster than its inputs, leading to decreasing long-run average costs. They provide a competitive advantage and can be internal or external. Buying ingredients in bulk for a restaurant is an economy of scale; the more you buy, the cheaper the price per unit, reducing your average cost per meal.

Internal economies of scale — Internal economies of scale are the benefits gained by a firm as a result of its own decision to produce on a larger scale.

These advantages arise from within the firm itself as it grows, such as technical efficiencies from specialised machinery, bulk purchasing discounts, or specialised management. They lead to a downward-sloping LRAC. A large supermarket chain can buy huge quantities of milk directly from a dairy at a much lower price per litre than a small corner shop, which is an internal purchasing economy of scale.

External economies of scale — External economies of scale are particular benefits received by all the firms in an industry as a direct consequence of the growth of that industry.

These benefits arise from the overall expansion of the industry, not just a single firm's growth. Examples include a skilled labour pool, improved infrastructure, or specialist suppliers emerging in a concentrated area. If many tech companies set up in one city, a pool of skilled IT workers becomes available, and specialist repair shops for tech equipment emerge, benefiting all tech firms in that city.

diseconomies of scale — Diseconomies of scale occur when a firm’s costs per unit of output increase as the scale of output continues to increase beyond a certain size.

This situation is represented by the upward-sloping section of the LRAC curve. They typically arise from problems of management coordination, communication, and worker morale in very large, complex organisations. Imagine a very large school with thousands of students; it might become harder to manage, communicate effectively, and maintain individual student attention, leading to higher 'cost' per student in terms of quality or resources.

External diseconomies — External diseconomies are disadvantages that may be seen in the form of traffic congestion, land shortages, and shortages of skilled labour due to the excessive concentration of economic activities in a narrow geographical location.

These are disadvantages that affect all firms in an industry due to the overall growth and concentration of that industry in a specific area. They lead to an upward shift in the LRAC for all firms. If too many factories are built in one industrial zone, traffic jams might increase delivery times and costs for all factories, and land prices might skyrocket, affecting everyone.

Total revenue (TR) — Total revenue (TR) represents the sales of a firm and is obtained by multiplying the price of a good (P) by the number of units sold (Q).

It is the total income a firm receives from selling its goods and services over a period. Understanding TR is fundamental to calculating profit and making pricing decisions. If a baker sells 50 loaves of bread at $3each,theirtotalrevenueis$150.

Average revenue (AR) — Average revenue (AR) is the revenue per unit of output sold.

It is calculated by dividing total revenue by the quantity sold. For a firm, its demand curve is its average revenue curve, showing the price per unit at different quantities. If a company earns $1000fromselling100items,theaveragerevenueis$10 per item.

Marginal revenue (MR) — Marginal revenue (MR) is the additional revenue arising from the sale of an additional unit of output.

It is the change in total revenue divided by the change in output. Firms use MR to decide whether to produce an extra unit, comparing it to marginal cost. If selling 10 books brings in $100,andselling11booksbringsin$108, the marginal revenue of the 11th book is $8.

normal profit — Normal profit is the minimum level of profit an entrepreneur will expect to reflect what could have been earned elsewhere with the resources that are available.

It is considered a cost of production because without it, the entrepreneur would not remain in business. It represents the opportunity cost of the entrepreneur's capital and effort, and is included in total costs. If you could earn $50,000ayearworkingforsomeoneelse,then$50,000 is your normal profit for running your own business; anything less, and you might as well work for someone else.

supernormal profit — Supernormal profit is any profit over and above normal profit.

Also known as economic profit, it signals to other firms that a market is attractive, potentially leading to new entrants. It indicates that a firm is earning more than the minimum required to stay in business. If your normal profit is $50,000,andyourbusinessactuallyearns$70,000, then the extra $20,000 is supernormal profit.

Subnormal profit — Subnormal profit is when the profit that is earned by a firm is less than normal profit.

If a firm consistently makes subnormal profit, it indicates that its resources could earn a better return elsewhere. This is a signal for the firm to consider withdrawing from the market in the long run. If your normal profit is $50,000,butyourbusinessonlyearns$30,000, then you are making a subnormal profit, meaning you'd be better off doing something else with your resources.

Perfect competition — An ideal market structure where there are many firms, freedom of entry into the industry with all firms producing identical products, firms are price takers and there is perfect information for all firms in the market.

This model serves as a benchmark for efficiency, as supernormal profits are competed away in the long run, leaving only the most efficient firms making normal profit. Firms have no market power and cannot influence price, much like vendors at a farmers' market selling identical apples.

Imperfect competition — A collective term for market structures other than perfect competition, including monopoly, monopolistic competition, oligopoly, and natural monopoly.

These market structures deviate from the ideal of perfect competition due to factors like fewer firms, product differentiation, barriers to entry, or imperfect information, leading to varying degrees of market power for firms. This is like a shopping mall with diverse stores, from unique boutiques to large chains.

Monopolistic competition — A market structure where there are many firms and freedom of entry into an industry, but firms have some control over the product and its price due to product differentiation.

Firms are price makers but face a relatively elastic demand curve due to many substitutes. They can make supernormal profits in the short run, but free entry of competitors eliminates these in the long run, leading to normal profits, similar to local restaurants competing with unique recipes.

Oligopoly — A market situation where the total output is concentrated in the hands of a few firms, leading to interdependence in their decision-making.

Oligopolistic firms have market power and can erect barriers to entry. Their decisions on price and output are interdependent, meaning each firm must consider the reactions of its rivals, much like the mobile phone network industry where providers react to competitors' changes.

Monopoly — A market structure where there is a single seller in the market, or one firm dominates the market due to a very large market share.

A pure monopoly has a single firm controlling the entire output, while a dominant monopoly has a significant market share (e.g., over 25% or 40% in the UK). Monopolies are price makers and are protected by substantial barriers to entry, allowing them to earn supernormal profits in the long run, similar to a single company owning all water supply infrastructure in a city.

Pure monopoly — A market situation where there is just one firm producing a good or service for the entire market.

This is the most extreme form of monopoly, where the single firm faces the entire market demand curve and has complete control over price or quantity, subject to consumer demand. It is protected by substantial barriers to entry, like a historical national postal service.

Natural monopoly — A particular form of monopoly where long-run average costs are lower when there is just one firm in the industry.

This occurs when fixed costs are very high, and economies of scale are so substantial that a single firm can supply the entire market at a lower average cost than multiple competing firms. It is often seen in industries with extensive infrastructure, such as a railway network.

Barriers to entry — A range of obstacles that deter or prevent new firms from entering a market to compete with existing firms.

These barriers give existing firms market power, allowing them to make decisions without the immediate threat of new competition. They can be legal (e.g., patents), market-based (e.g., brand loyalty), cost-related (e.g., high start-up costs), or physical (e.g., control of raw materials), acting like a high wall around a castle.

Sunk costs — Costs that cannot usually be recovered if a firm is shutting down, as the resources are not easily transferred to other uses.

These costs act as a barrier to exit from an industry because the capital investment will be lost. The risk of incurring sunk costs deters potential entrants, thus also acting as a barrier to entry, similar to a highly specialised machine that cannot be repurposed.

Product differentiation — The process of making a product different from those of competitors, often through quality, physical differences, branding, or marketing.

This gives firms a slight degree of monopoly power, allowing them some control over price. It is a key characteristic of monopolistic competition and can also be present in oligopolies, much like different brands of soft drinks are differentiated by taste and branding.

Price takers — Firms that have no influence on the market price and must accept the ruling price determined by the forces of market demand and the output of all firms.

This is a characteristic of perfect competition, where individual firms are so small relative to the market that their output decisions do not affect the overall market price. Their demand curve is perfectly elastic, like a single wheat farmer selling at the global market price.

Price makers — Firms that have some influence on the market price and can choose the price to charge or the quantity to supply, but not both.

This is a characteristic of imperfectly competitive markets (monopoly, oligopoly, monopolistic competition) where firms face a downward-sloping demand curve. Their ability to set prices depends on their market power and the availability of substitutes, similar to a company with a patented new drug.

Shutdown price — The price at which a firm can continue in production making short-run losses, as long as the price received covers the average variable cost (AVC).

If the price falls below AVC, the firm should shut down immediately because it cannot even cover its variable costs, and its loss would be greater than its fixed costs. Above AVC but below ATC, it covers variable costs and some fixed costs, like a restaurant staying open if it covers ingredients and wages, but not rent.

X-inefficiency — A type of productive inefficiency where a firm is not producing at the lowest possible cost for a given level of output.

This often occurs in monopolies or state-owned enterprises due to a lack of competitive pressure, leading to complacency, poor management, or excessive costs (e.g., too many workers, inefficient use of capital), similar to a government department with a guaranteed budget.

Concentration ratio — A measure of the market share of a given number of firms (usually 3, 4 or 5) in relation to the total market size.

It is calculated by adding the percentage market shares of the top firms, typically based on sales value, physical output, or number of employees. A higher ratio indicates a less competitive market, closer to oligopoly or monopoly, like looking at the top 4 pizza chains' share of total sales.

Collusion — An anti-competitive action by producers where firms co-operate with rivals, often informally through price leadership or formally through cartels, to restrict competition.

The objective of collusion is to maximise the profits of the whole group by acting as a single seller, often by agreeing on prices or output levels. Informal collusion is not illegal, but formal cartels are, similar to airlines secretly agreeing to raise ticket prices.

Cartel — A formal price or output agreement between firms in an industry to restrict competition.

By joining a cartel and agreeing prices or output levels, firms operate as a single seller, aiming to maximise their collective profit. Cartels are typically illegal in most countries due to their anti-competitive nature, like OPEC agreeing on oil production levels.

Price leadership — A form of informal collusion where firms automatically follow the lead of one dominant firm in the group when adjusting prices.

The dominant firm sets the price, and other firms in the oligopoly follow suit, leading to price stability without a formal agreement. This helps avoid price wars and maximises group profits, as when one major airline announces a fare increase and others follow.

Prisoner’s Dilemma — A concept in game theory that explains why two otherwise rational people might not co-operate, even if it appears to be in their best interest to do so.

It illustrates how individual self-interest can lead to a collectively suboptimal outcome. In oligopolies, it can explain why firms might break collusive agreements (like cartels) by increasing output, even though all firms would be better off if they cooperated, similar to two students deciding whether to work hard or slack off on a group project.

Kinked demand curve — A traditional model of oligopoly used to explain how firms react to each other’s behaviour, assuming price rigidity.

The model assumes that if an oligopolist raises its price, rivals will not follow, leading to a large fall in demand (elastic). If it lowers its price, rivals will follow, leading to a small increase in demand (inelastic). This creates a 'kink' at the current price, suggesting price stability, like friends deciding where to eat.

Non-price competition — Competitive strategies that do not involve changing the price of a product, such as advertising, product innovation, brand proliferation, market segmentation, and process innovation.

Firms, especially in oligopolies and monopolistic competition, use non-price competition to increase revenue, strengthen market power, and differentiate their products without triggering price wars. It aims to shift the demand curve or make it less elastic, like car companies adding new features or advertising.

Predatory pricing — A strategy where existing large producers cut their price in order to eliminate any high-cost producers or new firms that enter the industry.

This involves deliberately setting prices below average cost to drive competitors out of the market, with the intention of raising prices once competition is eliminated. It is often illegal, like a large supermarket selling milk below cost to force out a local dairy.

Limit pricing — A strategy where firms deliberately set a low price and temporarily abandon profit maximisation as their objective to deter new entrants.

By setting a price below the level that would attract new firms, existing firms sacrifice some short-run profit to maintain their market share and prevent future competition. This can be a form of collusion if agreed upon by multiple firms, like an internet provider offering slightly lower prices to deter new competitors.

Price discrimination — A practice where a monopolist chooses to split up the output and sell it at different prices to different customers.

This allows the monopolist to capture more consumer surplus and convert it into producer surplus, thereby increasing its profits. It requires market power, the ability to segment customers, and prevention of resale, such as a cinema charging different prices for student and adult tickets.

Contestable market — A market where potential competitors can influence the conduct of firms currently in the market, even if there are few actual competitors.

The key features are low or zero barriers to entry and exit (costless entry and exit, no sunk costs). The threat of 'hit and run' entry by new firms forces existing firms to behave more competitively, even if they are a monopoly or oligopoly, like the domestic airline industry where new airlines can easily enter or exit routes.

Hit and run entry — A characteristic of contestable markets where a firm is attracted to enter a market due to high profits, takes a share of the profits, and then leaves once profit levels fall back to normal.

This behaviour is possible because entry and exit are costless (no sunk costs). The threat of such entry forces incumbent firms to keep prices low and earn only normal profits in the long run, similar to a pop-up shop making quick profits during a festival and then closing.

Internal growth — A firm decides to retain some of the profit rather than pay it out to the owners, putting it back into the business as new investment to increase productive capacity.

This type of growth involves a firm using its retained profits to expand its existing operations or build new facilities, much like a person saving money from their salary to buy a bigger house. It allows a firm to expand its operations and output from within, using its own accumulated resources, and is common in capital-intensive activities with expanding markets, often during economic boom periods.

External growth — The business expands by joining with others via takeovers or mergers.

This method of growth involves combining with other existing firms, either through a mutually agreed merger or a takeover where one firm acquires control of another, similar to two small sports teams combining to form one larger, stronger team. It can be a quicker route to expansion, especially when fixed costs are high.

Horizontal integration — A process or strategy used by firms to strengthen their position in an industry, involving the merger or acquisition of a business that is in the same sector of an industry.

This type of integration occurs between firms at the same stage of production in the same industry, such as two competing coffee shop chains merging. Its prime motives are to achieve economies of scale, increase market power, and reduce competition, potentially leading to abnormal profits.

Vertical integration — Where a firm grows by moving into a forward or backward stage of its production process or supply chain.

This can be 'forward' (e.g., a manufacturer buying a retailer) or 'backward' (e.g., a manufacturer buying a supplier of raw materials), similar to a bakery buying a wheat farm or opening its own chain of sandwich shops. Benefits include improved security and quality of supplies and reduced supply chain costs, but it can lead to higher costs if not managed effectively.

Conglomerate — A firm whose growth comes from the purchase of unrelated businesses.

The primary rationale for conglomerate growth is to spread risk across diverse business interests, much like a company owning a car manufacturer, a hotel chain, and a tea plantation. Each company within a conglomerate typically operates independently, and losses from one subsidiary can be offset by profits from others.

Cartel — A formal agreement between member firms in an industry to limit competition.

Cartels typically involve fixing quantities to be produced or prices for products, aiming to maximise profits similar to a monopolist, much like a group of students agreeing to all charge the same high price for their tutoring services. Their long-term survival depends on high barriers to entry and the absence of internal disagreements or external threats.

Principal–agent problem — Occurs when one person (the agent) makes decisions on behalf of another person (the principal), but the agent may act in their own interest rather than the principal's.

This problem arises due to asymmetric information, where the agent (e.g., firm management) has more information than the principal (e.g., shareholders), similar to a mechanic recommending unnecessary repairs to increase their own profit. It can lead to a misallocation of resources if agents pursue personal prestige or career development over the firm's profit maximisation.

Asymmetric information — A situation where one party in a transaction has more or superior information compared to another.

In the context of the principal-agent problem, managers (agents) possess more detailed, day-to-day information about the firm's operations and growth plans than the owners (principals), much like a used car seller knowing more about a car's history than the buyer. This informational imbalance can lead to decisions that are not in the principal's best interest.

Moral hazard — Occurs when one party takes on more risk because another party has agreed to bear the cost of those risks.

In the principal-agent context, if principals cannot fully monitor agents, agents might take actions that benefit themselves (e.g., risky growth strategies for prestige) knowing that the principals will bear the financial consequences if things go wrong, similar to someone with full insurance being less careful with their car. This is a consequence of asymmetric information.

Agency cost — The costs incurred by principals in monitoring agents and the costs arising from agents acting in their own self-interest.

These costs include expenses for monitoring agents' actions, structuring incentives to align interests, and the potential losses from agents making decisions that do not maximise the principal's welfare, much like the extra money paid for a trusted mechanic or time spent researching reviews. It represents the inefficiency arising from the principal-agent problem.

Profit maximisation — Profit maximisation involves achieving the greatest difference between the total revenue and total cost (including normal profit).

This is the traditional objective assumed by economists, where firms produce at the output level where marginal cost equals marginal revenue (MC=MR). Achieving supernormal profit is a reward for taking risks, much like a baker finding the 'sweet spot' where the extra money from selling one more cake just covers its extra cost, leading to the biggest overall profit.

Principal–agent problem — The principal–agent problem arises when the management (agents) may have different objectives to the shareholders (principals) of a firm.

This conflict of interest can lead managers to pursue objectives like revenue maximisation, growth, or personal benefits rather than strict profit maximisation, especially in large firms where ownership is divorced from control. It's like a gardener (agent) you hire to maintain your garden (principal) who might prefer expensive tools or longer breaks, benefiting them but not necessarily you.

Profit satisficing — Profit satisficing occurs when a firm seeks to make a reasonable or minimum level of profit, sufficient to satisfy the shareholders but also to keep other stakeholders happy.

This objective acknowledges that firms operate within a complex environment with various interest groups (shareholders, workers, consumers) whose expectations need to be met. It implies sacrificing some potential short-term profits for broader stakeholder satisfaction and long-term stability, similar to a small restaurant aiming for comfortable profits while also valuing happy staff and loyal customers.

Sales maximisation — Sales maximisation is the objective to maximise the volume of sales rather than the total revenue from sales.

This objective leads to a higher output than revenue maximisation, specifically up to the break-even output where total revenue just covers total cost. It might be pursued to gain market share, achieve economies of scale, or deter new entrants, sometimes involving cross-subsidisation, much like a new streaming service offering low introductory prices to attract a large user base.

Cross-subsidisation — Cross-subsidisation occurs when the profit from one part of a firm is used to offset losses made elsewhere.

This strategy allows a firm to maintain loss-making operations, often for social objectives or to support a broader business strategy like sales maximisation. It's common in multi-product firms or state-owned enterprises, similar to a bus company using profits from busy routes to maintain less popular rural services.

Revenue maximisation — Revenue maximisation is an alternative theory of a firm’s behaviour where senior managers are interested in increasing sales and maximising total revenue from sales.

This objective is often linked to managerial salaries and bonuses, which are typically based on total revenue rather than profits. Production continues to the point where marginal revenue (MR) equals zero, resulting in a higher output than profit maximisation, much like a concert promoter aiming to fill a venue and maximise total ticket sales, even if it means slightly lower prices per ticket.

Cost-plus pricing — Cost-plus pricing is a technique where a firm works out the average total cost and then adds on a standard profit margin to determine the selling price.

This method is a practical approach to setting prices but is unlikely to result in maximum profit because it doesn't directly consider demand elasticity or marginal revenue. It's often used due to the difficulty in identifying the profit-maximising output, similar to a builder adding a fixed percentage to material and labour costs to set a house price.

Price discrimination — Price discrimination is a pricing policy used by firms to increase profits by reducing consumer surplus and converting this into producer surplus, by charging different prices to different consumers for the same product.

This policy requires the firm to have some control over price (a downward-sloping demand curve) and to be able to segment the market and prevent resale. It is not possible under perfect competition, much like an airline charging different prices for the same seat based on booking time or fare type.

First degree price discrimination — First degree price discrimination is a situation where the firm sells each unit of a product to a different consumer, charging each the maximum price that they are willing to pay.

This is the most extreme form, where the firm extracts all consumer surplus. It is difficult to implement in practice and is most commonly seen in service sectors where prices are unique to each transaction and resale is impossible, like a private tutor charging personalised rates based on a student's ability to pay.

Second degree price discrimination — Second degree price discrimination is where consumers are only willing to purchase more of a product if price falls as more and more units are bought, meaning a higher price is charged for the first unit followed by a lower price as successive units are purchased.

This type involves quantity-based discounting, where the price per unit decreases as the quantity purchased increases. It benefits both consumers (lower average price for more units) and the firm (increased output, revenue, and profit), similar to buying a single can of soda for $2butapackofsixfor$10.

Third degree price discrimination — Third degree price discrimination is the most common form, requiring firms to actively discriminate between groups of consumers based on their different price elasticities of demand for the product.

Consumers with inelastic demand are charged a higher price, while those with elastic demand are charged a lower price. This requires the firm to segment the market and prevent resale between groups, such as a cinema offering student discounts where students have more elastic demand.

Limit pricing — Limit pricing is a pricing policy applied in monopolies and oligopolies, involving firms setting a lower short-run price to deter new firms from entering their market.

This strategy sacrifices short-run profit maximisation to create a barrier to entry. The established firm increases output or services to a level that makes it unprofitable for potential new entrants to compete, much like an established internet provider temporarily dropping prices when a new competitor enters.

Predatory pricing — Predatory pricing occurs when an established firm responds to a new entrant by setting a price so low that the new firm cannot make a profit and is forced out of the market.

Once the rival is eliminated, the established firm raises its prices back to their former level. This practice is often illegal due to its anti-competitive nature and can also be used by established firms against each other to gain market share, similar to a large supermarket slashing prices below cost to force a smaller rival out.

Price leadership — Price leadership is a common feature of oligopolistic markets where all firms accept the price set by the leading firm, which is often the firm with the largest market share or is the brand leader.

This policy helps firms avoid price competition, allowing them to maximise total profits for all firms while focusing on non-price competition. Other firms quickly follow the leader's price changes, whether increases or decreases, much like major petrol companies following a price increase by one leading firm.