Final Exam Study Guide: Principles of Microeconomics

Chapter 4: Demand, Supply, and Equilibrium

Meaning of Markets

Markets are systems or environments where buyers and sellers interact to exchange goods and services. They play a central role in determining prices and allocating resources efficiently.

• Types of Markets: Physical (e.g., farmer’s market) and virtual (e.g., online marketplaces).

• Market Participants: Consumers (demand side) and producers (supply side).

Law of Demand

• States that, ceteris paribus (all else equal), as the price of a good increases, the quantity demanded decreases, and vice versa.

• Demand Curve: Downward sloping, showing the inverse relationship between price and quantity demanded.

Law of Supply

• States that, ceteris paribus, as the price of a good increases, the quantity supplied increases, and vice versa.

• Supply Curve: Upward sloping, showing the direct relationship between price and quantity supplied.

Market Equilibrium

• The point where the quantity demanded equals the quantity supplied.

• Equilibrium Price: The price at which the market clears (no shortage or surplus).

• Equilibrium Quantity: The quantity bought and sold at the equilibrium price.

Shifts in Demand and Supply

• Demand Shifters: Income, tastes, prices of related goods, expectations, number of buyers.

• Supply Shifters: Input prices, technology, expectations, number of sellers.

Types of Markets

• Perfect Competition: Many buyers and sellers, identical products, free entry and exit.

• Monopoly: Single seller, unique product, high barriers to entry.

• Oligopoly: Few sellers, products may be identical or differentiated.

• Monopolistic Competition: Many sellers, differentiated products.

Market Failures

• Situations where markets do not allocate resources efficiently on their own (e.g., externalities, public goods).

Chapter 5: Consumers and Incentives

Budget Constraints

• Shows the combinations of goods a consumer can afford given their income and prices.

• Equation: $P_x X + P_y Y = I$

Preferences and Utility

• Utility: Satisfaction or happiness derived from consuming goods and services.

• Marginal Utility: Additional satisfaction from consuming one more unit of a good.

Optimization

• Consumers maximize utility subject to their budget constraint.

• Optimal consumption bundle occurs where the marginal utility per dollar is equal across all goods: $\frac{MU_x}{P_x} = \frac{MU_y}{P_y}$

Chapter 8: Trade

Production Possibilities Curve (PPC)

• Shows the maximum combinations of two goods that can be produced with available resources and technology.

• Points inside the curve are inefficient; points on the curve are efficient; points outside are unattainable.

Comparative and Absolute Advantage

• Absolute Advantage: Ability to produce more of a good with the same resources.

• Comparative Advantage: Ability to produce a good at a lower opportunity cost.

• Trade allows countries to specialize in goods where they have comparative advantage, increasing overall efficiency and welfare.

Chapter 9: Externalities and Public Goods

Externalities

• Costs or benefits of a market activity borne by a third party.

• Negative Externality: Imposes costs (e.g., pollution).

• Positive Externality: Confers benefits (e.g., education).

Public Goods

• Goods that are non-excludable and non-rivalrous (e.g., national defense).

• Markets may underprovide public goods due to the free-rider problem.

Chapter 12: Monopoly

Key Characteristics of Monopoly

• Single seller, unique product, no close substitutes, high barriers to entry.

Barriers to Entry

• Legal barriers (patents, licenses), control of resources, economies of scale, network effects.

Monopoly Pricing and Output

• Monopolist maximizes profit where marginal revenue equals marginal cost ($MR = MC$).

• Price is set above marginal cost, leading to lower output and higher prices compared to perfect competition.

Price Discrimination

• Charging different prices to different consumers for the same product, not based on cost differences.

• First-degree (perfect) price discrimination: Each consumer is charged their maximum willingness to pay.

• Second-degree price discrimination: Price varies by quantity purchased or product version.

• Third-degree price discrimination: Price varies by consumer group (e.g., student discounts).

Example:

• Movie theaters charging different prices for children, adults, and seniors.