Principles of Microeconomics: Final Exam Study Guide

Chapter 4: Demand, Supply, and Equilibrium

The Meaning of Markets

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

• Market Types: Competitive, monopolistic, oligopolistic, etc.

• Role of Prices: Prices signal information and coordinate economic activity.

• Example: The stock market facilitates the buying and selling of shares among investors.

Demand and Supply Curves

The demand curve shows the relationship between the price of a good and the quantity demanded, holding other factors constant. The supply curve shows the relationship between price and quantity supplied.

• Law of Demand: As price decreases, quantity demanded increases.

• Law of Supply: As price increases, quantity supplied increases.

• Equation: $Q_d = a - bP$ (Demand), $Q_s = c + dP$ (Supply)

• Example: If the price of apples falls, consumers buy more apples.

Market Equilibrium

Market equilibrium occurs where the quantity demanded equals the quantity supplied. The equilibrium price is where the demand and supply curves intersect.

• Equation: Set $Q_d = Q_s$ and solve for $P$.

• Surpluses and Shortages: If price is above equilibrium, surplus occurs; if below, shortage occurs.

• Example: At equilibrium, the market for wheat clears with no excess supply or demand.

Consumer and Market Demand

Individual demand refers to the quantity a single consumer will buy at various prices. Market demand is the sum of all individual demands.

• Equation: $Q_{market} = Q_1 + Q_2 + ... + Q_n$

• Example: If three consumers each demand 2, 3, and 5 units, market demand is 10 units.

Supply Schedules and Curves

Supply schedules list quantities supplied at different prices. The supply curve graphically represents this relationship.

• Shifts in Supply: Caused by changes in input prices, technology, or number of sellers.

• Example: A technological improvement shifts the supply curve rightward.

Market Disequilibrium

Disequilibrium occurs when market price is not at the equilibrium level, resulting in either excess supply or excess demand.

• Adjustment Process: Prices tend to move toward equilibrium due to market forces.

Types of Market Distinguishment

Markets can be distinguished by the number of buyers and sellers, product differentiation, and barriers to entry.

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

• Monopoly: Single seller, unique product.

Chapter 6: Sellers and Incentives

Seller's Problem

Sellers aim to maximize profit by choosing optimal input combinations and output levels.

• Inputs: Labor, capital, raw materials.

• Costs: Fixed and variable costs.

• Profit Maximization: Occurs where marginal cost equals marginal revenue.

• Equation: $MR = MC$

Production Decisions

Producers decide how much to produce based on input costs, technology, and market prices.

• Short Run vs. Long Run: In the short run, some inputs are fixed; in the long run, all inputs are variable.

• Example: A bakery may hire more workers in the short run but buy new ovens in the long run.

Cost Functions

Cost functions describe the relationship between output and total cost.

• Equation: $TC = FC + VC$

• Average Cost: $AC = TC/Q$

• Marginal Cost: $MC = rac{ riangle TC}{ riangle Q}$

Accounting vs. Economic Profit

Accounting profit is total revenue minus explicit costs. Economic profit subtracts both explicit and implicit costs.

• Equation: $\text{Economic Profit} = \text{Total Revenue} - (\text{Explicit Costs} + \text{Implicit Costs})$

• Example: If a firm earns $100,000 in revenue, pays $60,000 in explicit costs, and has $20,000 in implicit costs, economic profit is $20,000.

Producer Surplus

Producer surplus is the difference between the price sellers receive and the minimum price they are willing to accept.

• Equation: $\text{Producer Surplus} = \text{Price Received} - \text{Minimum Acceptable Price}$

Competitive Equilibrium in the Long Run

In the long run, firms enter or exit the market until economic profit is zero and resources are allocated efficiently.

• Entry and Exit: Firms enter when profit is positive, exit when negative.

Chapter 8: Trade

Production Possibilities Curve (PPC)

The PPC shows the maximum combinations of two goods that can be produced with available resources and technology.

• Efficient Points: On the curve.

• Inefficient Points: Inside the curve.

• Impossible Points: Outside the curve.

Opportunity Cost

Opportunity cost is the value of the next best alternative forgone when making a choice.

• Equation: $\text{Opportunity Cost} = \frac{\text{Loss in Good Y}}{\text{Gain in Good X}}$

Comparative Advantage

A country or individual has comparative advantage if it can produce a good at a lower opportunity cost than others.

• Basis for Trade: Specialization and exchange increase total output.

• Example: If Country A can produce wheat more efficiently than Country B, it should specialize in wheat.

Terms of Trade

Terms of trade refer to the rate at which goods are exchanged between countries.

• Equation: $\text{Terms of Trade} = \frac{\text{Exports}}{\text{Imports}}$

Trade Between Countries

Trade allows countries to consume beyond their PPC by specializing according to comparative advantage.

• Example: Denmark exports dairy products and imports electronics from Japan.

Chapter 9: Externalities and Public Goods

Externalities

Externalities are costs or benefits that affect third parties not directly involved in a transaction.

• Negative Externality: Pollution from a factory affects nearby residents.

• Positive Externality: Vaccination benefits society by reducing disease spread.

Private Solutions to Externalities

Private solutions include negotiation, property rights, and contracts to internalize externalities.

• Coase Theorem: If property rights are well-defined and transaction costs are low, parties can negotiate efficient outcomes.

Public Solutions to Externalities

Government interventions include taxes, subsidies, regulation, and tradable permits.

• Example: Carbon tax to reduce greenhouse gas emissions.

Public Goods

Public goods are non-excludable and non-rivalrous, meaning one person's use does not reduce availability to others.

• Examples: National defense, street lighting.

• Free Rider Problem: Individuals benefit without paying, leading to under-provision.

Common Resource Goods and Tragedy of the Commons

Common resources are rivalrous but non-excludable, leading to overuse and depletion.

• Example: Overfishing in public waters.

Chapter 12: Monopoly

Characteristics of Monopoly

A monopoly exists when a single firm is the sole producer of a product with no close substitutes and significant barriers to entry.

• Barriers to Entry: Legal restrictions, control of resources, economies of scale.

Profit Maximization in Monopoly

Monopolists maximize profit by producing where marginal revenue equals marginal cost, but price exceeds marginal cost.

• Equation: $MR = MC$

• Price Setting: Monopolists set price above competitive levels.

Inefficiencies of Monopoly

Monopolies lead to deadweight loss, reduced consumer surplus, and allocative inefficiency.

• Deadweight Loss: Lost welfare due to reduced output and higher prices.

Price Discrimination

Price discrimination occurs when a firm charges different prices to different consumers for the same product.

• Types: First-degree (perfect), second-degree, third-degree price discrimination.

• Example: Movie theaters charging different prices for children and adults.