Principles of Microeconomics Final Exam, Key Concepts

Consumer Theory

Consumer theory examines how individuals decide what goods and services to buy based on their preferences, income, and prices, aiming to maximize their satisfaction or utility.

Consumer constraints

Consumer constraints refer to the limits or restrictions that consumers face when making choices about what goods and services to buy. These constraints often include budget limits, prices of goods, and time availability, which together determine what a consumer can afford to purchase.

Budget Constraint

A budget constraint shows all the combinations of goods and services that a consumer can buy with their limited income at given prices. It represents the trade-offs a consumer faces because they cannot spend more than their income.

Affordable Set

The affordable set contains all possible bundles of goods that a consumer can purchase with their given income and the prices of those goods.

Budget Equation

The budget equation is a mathematical expression that represents the budget constraint. It states that the total spending on goods must equal the consumer's income, typically written as p1x1 + p2x2 = I, where p1 and p2 are prices, x1 and x2 are quantities, and I is income.

Budget Line

The budget line represents all combinations of two goods that a consumer can buy with a given income and prices, showing the maximum affordable consumption bundles.

Combinations of Goods

Combinations of goods are various quantities of different products that a consumer might consider buying within their budget constraint.

Expenditure Constraint

The expenditure constraint is the limit on total spending a consumer faces, determined by their income and the prices of goods.

Feasible Consumption Bundle

A feasible consumption bundle is a combination of goods that a consumer can buy without exceeding their budget. It lies on or below the budget line.

Income Limitation

Income limitation refers to the restriction on a consumer's affordable consumption choices based on the amount of money they have available to spend.

Consumer Choice Theory

Consumer choice theory studies how individuals decide what to buy based on their preferences, income, and the prices of goods and services, while facing budget constraints.

Indifference Curve Analysis Basics

Indifference Curve Analysis Basics involves looking at curves that show all combinations of two goods that give a consumer the same level of satisfaction or utility.

Marginal Rate of Substitution

The marginal rate of substitution measures how much of one good a consumer is willing to give up to get one more of another good, keeping their satisfaction the same.

Optimal Consumption Bundle

The optimal consumption bundle is the specific combination of goods that maximizes a consumer's utility, based on their preferences, income, and the prices of goods.

Tangency Condition

Tangency Condition refers to the point where the consumer's budget line touches an indifference curve, indicating the optimal consumption choice where the rate of substitution equals the price ratio.

Utility Maximization Concept

Utility Maximization Concept is the idea that consumers choose the combination of goods and services that gives them the highest satisfaction or happiness, given their budget limits.

Utility Subject to Constraint

Utility Subject to Constraint refers to the concept that consumers seek to maximize their happiness while facing limits such as income or prices that restrict their choices.

Price and Income Changes

Price and income changes refer to how variations in the prices of goods or a consumer’s income affect the consumer’s ability to buy different combinations of goods.

Real Income

Real income is the purchasing power of a consumer's income, adjusted for changes in prices. It shows how much goods and services income can actually buy.

Relative Prices

Relative prices are the prices of one good compared to another. They show how much of one good must be given up to buy a unit of another good, affecting the consumer's choices under a budget constraint.

Good X Price to Good Y Price Ratio

Good X price to good Y price ratio is the price of Good X divided by the price of Good Y; it represents the relative price consumers face when choosing between the two goods.

Slope of Budget Line

The slope of the budget line equals the negative ratio of the prices of the two goods. It shows the rate at which a consumer can trade one good for another while staying within their budget.

Consumption

Consumption is the process by which consumers use goods and services to satisfy their wants and needs. It represents the amount and type of goods and services that individuals or households purchase and use.

Consumer Preferences

Consumer preferences refer to the way individuals rank different goods or bundles of goods based on the satisfaction they provide.

Completeness

Completeness means that a consumer can compare and rank all possible bundles of goods, deciding which one is preferred or if they are equally preferred.

Monotonicity

Monotonicity assumes that more of a good is always better, so consumers prefer bundles with more of at least one good and not less of the others.

Preference Ordering

Preference Ordering is the ranking of different bundles of goods according to a consumer’s preferences from most to least preferred.

Indifference Curve

An indifference curve is a graph that shows all combinations of goods that give the consumer the same level of satisfaction or utility. On this curve, the consumer does not prefer one bundle over another.

Higher Indifference Curves

Higher indifference curves represent greater levels of consumer satisfaction because they show combinations of goods that provide more utility than lower curves.

Marginal Rate of Substitution

The marginal rate of substitution is the amount of one good a consumer is willing to give up to get one more unit of another good, keeping their overall utility unchanged.

Utility Function

A utility function is a mathematical representation that assigns a numerical value to each possible bundle of goods, reflecting the level of satisfaction or happiness a consumer derives from that bundle.

Diminishing Marginal Utility

Diminishing marginal utility refers to the decrease in added satisfaction as a consumer consumes more units of a good.

Marginal Utility

Marginal utility is the additional satisfaction or benefit a consumer receives from consuming one more unit of a good, holding other factors constant.

Ordinal Utility

Ordinal utility refers to the ranking of different bundles of goods according to the level of satisfaction they provide. It considers only the order of preferences, not the specific magnitude of utility differences.

Utility Maximization

Utility maximization is the process by which consumers choose the combination of goods and services that provides the highest possible satisfaction, given their budget constraints.

Budget Constraint Concept

The budget constraint shows all the combinations of goods and services a consumer can buy with their limited income at current prices. It represents the limitation that a consumer cannot spend more money than they have.

Budget Line

The budget line is a graph that illustrates all affordable combinations of two goods based on the consumer's income and prices.

Consumer Equilibrium

Consumer equilibrium occurs when a consumer maximizes their utility given their budget constraint, choosing a combination of goods where no other choice can give them higher satisfaction at the prices they face.

Equality of Marginal Rate of Substitution and Price Ratio

This equality means the rate at which a consumer is willing to exchange one good for another (marginal rate of substitution) is exactly equal to the rate at which the market requires exchanging them (price ratio), indicating optimal consumption.

First Order Condition

The first order condition is the requirement that the slope of the indifference curve equals the slope of the budget line for utility maximization.

Optimal Consumption Bundle

The optimal consumption bundle is the set of quantities of different goods that a consumer selects to maximize utility given their budget and the prices of goods.

Income and Substitution Effects

The income and substitution effects describe how changes in the price of a good impact consumer choices. The substitution effect happens when consumers replace a good that has become relatively more expensive with a cheaper alternative. The income effect occurs when a price change affects a consumer's real purchasing power, making them feel richer or poorer, which influences the amount they buy.

Price Change and Consumer Choice

Price Change and Consumer Choice explain how changes in the price of a good affect consumer decisions and alter the combination of goods they buy to maximize utility.

Income and Substitution Decomposition

Income and Substitution Decomposition is the process of splitting the total change in consumption due to a price change into two parts: the substitution effect, from changing relative prices, and the income effect, from the consumer's changed purchasing power.

Optimal Consumption Bundle

The optimal consumption bundle is the set of goods a consumer selects to maximize utility given their budget constraint and the prices of goods.

Price Elasticity of Demand

Price Elasticity of Demand measures how sensitive the quantity demanded of a good is to changes in its price, calculated as the percentage change in quantity divided by the percentage change in price.

Total Effect of Price Change

The total effect of a price change is the overall change in the quantity demanded of a good when its price changes. It combines both the substitution effect, where consumers switch to cheaper alternatives, and the income effect, reflecting how purchasing power changes.

Substitution Effect

The substitution effect describes how a consumer changes their consumption of goods in response to a change in relative prices, substituting away from more expensive goods toward relatively cheaper ones.

Consumer Substitution Behavior

Consumer substitution behavior occurs when consumers buy more of a good that has become relatively cheaper and less of a good that has become relatively more expensive.

Marginal Rate of Substitution

Marginal rate of substitution (MRS) measures the amount of one good a consumer is willing to give up to get one more unit of another good while keeping satisfaction level constant.

Income Distribution

Income distribution refers to how total income is shared among individuals or groups in an economy, showing levels of inequality or equality within the population.

Functional Distribution

Functional distribution describes how income is divided among the factors of production—namely wages for labor, rent for land, interest for capital, and profits for entrepreneurs. It tells us which groups receive income from specific sources.

Factor Shares

Factor shares represent the proportion of total national income that is paid to each factor of production. For example, the labor share refers to the portion of income paid as wages, while the capital share is the portion paid as interest and profits.

Income Inequality

Income inequality is the unequal distribution of income across a population. It measures the gap between the richest and poorest individuals or groups, showing how unevenly income is spread in society.

Sources of Income Inequality

Sources of income inequality refer to the various factors that cause differences in income among people. These include differences in education, skills, work experience, discrimination, technological changes, and variations in capital ownership and labor market opportunities.

Minimum Wage Laws

Minimum wage laws set the lowest legal hourly pay workers can receive, which can reduce income inequality by lifting earnings for low-wage workers.

Income Redistribution Policies

Income redistribution policies are government actions designed to reduce income inequality by transferring income or wealth from richer to poorer groups. These policies include taxation, social welfare programs, and subsidies to support low-income individuals.

Taxation and Redistribution Policies

Taxation and redistribution policies are government actions that collect taxes from individuals or businesses and use that money to reduce income inequality by transferring resources to lower-income groups.

Tax Incidence

Tax incidence refers to who actually bears the burden of a tax, whether it is the consumer or the producer. It depends on how the tax affects prices and the responsiveness of supply and demand.

Poverty

Poverty is a state where a person or a group lacks enough income or resources to meet basic needs such as food, shelter, and clothing. It indicates material deprivation and economic hardship.

Economic Inequality

Economic inequality is the uneven distribution of income and wealth within a society, which can limit opportunities and increase poverty for disadvantaged groups.

Assumptions In Microeconomic Models

Assumptions in microeconomic models are simplified conditions or statements taken to be true to help explain economic behavior. They allow economists to focus on key factors by ignoring less important details, such as assuming rational behavior, perfect information, or competitive markets.

Perfect Information

Perfect information means that all economic agents have complete and instant knowledge about all relevant factors that affect their decisions. This means everyone knows everything necessary to make rational choices.

Scarcity of Resources

Scarcity of resources means that limited amounts of factors like time, money, labor, and materials are available to satisfy unlimited wants and needs.

Market Economy

A market economy is an economic system where decisions about what to produce, how to produce, and for whom to produce are made by individuals and businesses based on supply and demand. Prices are determined by competition in free markets.

Resource Allocation via Market

Resource allocation via market is the method by which resources are distributed to their best uses based on supply, demand, and prices.

Marginal Benefit vs Marginal Cost

Marginal benefit is the extra satisfaction from an action, while marginal cost is the extra cost of that action. Decisions are efficient when the marginal benefit equals the marginal cost.

Voluntary Trade

Trade that happens by mutual agreement without coercion, where all parties expect to gain.

Market Failures

Market Failures happen when a market does not allocate resources efficiently, leading to a loss of social welfare. Examples include externalities, public goods, and information asymmetry.

Goods

Goods are physical items that can be consumed or used to satisfy human wants and needs. They are classified in microeconomics into categories such as private goods, public goods, and common resources, each having distinct characteristics regarding consumption and rivalry.

Common Resources

Common resources are goods that are rivalrous but not excludable. This means people cannot be easily prevented from using them, but one person's use reduces the amount available for others. Examples include fish in the ocean and public pasture land.

Non-Excludability

Non-excludability means that it is difficult or impossible to prevent people who have not paid for a good from using it.

Tragedy of the Commons

The tragedy of the commons is a situation where individuals overuse and deplete a shared resource because they act in their own self-interest without considering the group's long-term welfare.

Private Goods

Private goods are products that are both excludable and rival in consumption. This means that people can be prevented from using them if they do not pay, and one person's use of the good reduces the amount available for others. Examples include food and clothing.

Excludability

Excludability means that it is possible to prevent people who do not pay for a good from using it. This characteristic usually applies to private goods, allowing producers to control who can consume the good.

Price Mechanism

The price mechanism is the process by which supply and demand interact to determine the price of a good, which then signals producers and consumers to adjust production or consumption accordingly.

Pure Private Goods

Pure private goods are items that are both excludable and rival in consumption. Typically, only paying customers can use them, and one person's consumption prevents another from using the same unit.

Rivalry in Consumption

Rivalry in consumption exists when one person's use of a good reduces the amount available for others.

Public Goods

Public goods are goods that are non-excludable and non-rivalrous. This means that no one can be prevented from using them, and one person's use does not reduce availability for others. Examples include national defense and clean air.

Collective Consumption

Collective consumption refers to the simultaneous use of a good by many individuals without diminishing its availability to others.

National Defense

National defense is a public good that protects a country from external threats and is non-excludable and non-rivalrous.

Non-Rivalry in Consumption

Non-rivalry in consumption means that one person's use of a good does not reduce the amount available for others. Multiple people can use the good at the same time without interfering with each other.

Information Asymmetry

Information asymmetry occurs when one party in a transaction has more or better information than the other, which can prevent the market from functioning efficiently and lead to problems like adverse selection and moral hazard.

Adverse Selection Problem

Adverse selection occurs when one party in a transaction has more information than the other, leading to the selection of poor-quality goods or high-risk individuals before a deal is made.

Concept of Principal-Agent Problem

The principal-agent problem occurs when a principal hires an agent to perform a task but cannot fully monitor the agent's actions, causing conflicts due to information asymmetry.

Hidden Information

Hidden information refers to a situation where one party in a transaction knows more about a relevant aspect, such as product quality, which is unknown to the other party.

Sources Of Market Failure

Sources of market failure are the main reasons why markets do not allocate resources efficiently on their own. These include factors like externalities, public goods, information problems, and market power. When these problems exist, markets may produce too much, too little, or the wrong types of goods and services.

Externalities Foundations

Externalities occur when a person's or firm's actions affect others in ways that are not reflected in market prices. They can be positive, like someone planting trees that benefit neighbors, or negative, like pollution that harms the environment. Externalities cause market failure because free markets may produce too much of a bad externality or too little of a good one.

Imperfect Competition

Imperfect competition describes market situations where some buyers or sellers can affect prices, contrasting with perfect competition where no individual can influence the market price. Examples include monopolies, oligopolies, and monopolistic competition. Because firms have control over prices, this can lead to market failure.

Market Power Basics

Market power refers to the ability of a single firm or a group of firms to influence the price or supply of a product or service. When a firm has market power, it can charge higher prices or restrict output, leading to inefficient market outcomes and market failure.

Income And Substitution Effect Basics

The Income Effect is the change in quantity demanded due to a change in consumer’s real income from a price change, while the Substitution Effect is the change in quantity demanded as consumers replace more expensive goods with cheaper alternatives.

Income Effect Concept

The income effect shows how a change in the price of a good affects consumers' real income, leading to a change in the quantity demanded.

Substitution Effect Concept

The substitution effect shows how consumers change their buying behavior by choosing a cheaper alternative when the price of a good rises, holding the consumer's real income constant.

Aggregation of Individual Demands

Aggregation of individual demands means combining the demand of all the consumers in the market to create the market demand, usually done by adding quantities demanded at each price.

Market Demand Curve

The market demand curve represents the total quantity of a good or service that all consumers in a market are willing and able to buy at various prices. It is found by adding up all individual demand curves in the market.

Law of Demand

The Law of Demand states that, all else being equal, as the price of a good or service decreases, the quantity demanded increases, and as the price increases, the quantity demanded decreases.

Inverse Relationship Between Price And Quantity Demanded

This means that when the price of a good rises, the quantity demanded falls, and when the price falls, the quantity demanded rises. It is a key part of the Law of Demand.

Quantity Demanded Changes

Quantity Demanded Changes refer to movements along the demand curve caused by price changes of the good itself. When price rises, quantity demanded falls, and when price falls, quantity demanded rises.

Price Ceilings

A price ceiling is a legal maximum price that can be charged for a good or service. It is set below the market equilibrium price to make the good more affordable, often leading to a shortage because quantity demanded exceeds quantity supplied.

Legal Maximum Price

An official price limit established by law that sellers cannot exceed when selling a product or service.