CLEP Microeconomics

Table of Contents

• [[#1. Basic Economic Concepts (10-16% of exam)]]
• [[#2. 2. Supply and Demand (15-20% of exam)]]
• [[#3. Theory of Consumer Choice (5-10% of exam)]]
• [[#4. Production and Costs (10-15% of exam)]]
• [[#5. Firm Behavior and Market Structure (25-33% of exam)]]
• [[#6. Factor Markets (6-12% of exam)]]
• [[#7. Market Failure and Role of Government (8-14% of exam)]]
• [[#Formulas]]
• [[#Exam]]

1. Basic Economic Concepts (10-16% of exam)

The study of how people allocate scarce resources

Production Possibilities Curve (PPC)

• Shows maximum output combinations with given resources in a snapshot of time
• Points on curve = efficient; inside = inefficient; outside = impossible

Comparative Advantage and Trade

• Law of Comparative Advantage: Difference in relative costs of production are key to determining patterns of trade
• Comparative Advantage: Lower opportunity cost in production
  • cannot have comparative advantage for both goods
• Absolute Advantage: Higher productivity/efficiency
• Specialization and trade leads to higher consumption for both parties
• Self Sufficiency: Producing everything for yourself

Economic Systems

Systems of production, allocation, exchange, and distribution

• Market Economy: Private ownership and allocation (capitalism)
  • Property Rights: Essential for market economies, ability to own (use, earn, transfer and enforce rights)
• Command Economy: Government ownership and allocation (communism)
  • Market Socialism: Planned ownership, Private allocation
• Property Rights: Legal framework for ownership and resource allocation

Marginal Analysis

Costs and benefits of one additional unit

• Profit Maximization: $\mathrm{\Delta }Benefit=\mathrm{\Delta }Cost$
  • Produce where Marginal Revenue = Marginal Cost
  • Vise versa for factors of production (labor)
• Consumer Maximization: $\frac{M{U}_x}{P_x}=\frac{M{U}_y}{P_y}$

2. Supply and Demand (15-20% of exam)

Market Equilibrium

• Equilibrium: Where supply and demand curves intersect ($P\star$, $Q\star$)
  • The invisible hand will pull toward this equilibrium
• Surplus: Price above equilibrium; quantity supplied > quantity demanded (floor)
• Shortage: Price below equilibrium; quantity demanded > quantity supplied (ceiling)
• Perfect Competition: we assume perfect competition - many buyers and sellers, identical goods, no barrier to entry or exit, perfect access to information, no externalities, no single agent is able to exert price control.
  • firms are price takers

Demand

• Comes from Buyer
• Shifters: Income, Preference, Related goods, Number of buyers, Future expectations
  • movement caused by change in price. Usually from changing supply
• Negative slope: consumers buy when MU = MC, decreasing marginal utility and variable consumer utility leads to a negative Demand Slope (Schedule).
• Compliments: consumed together. (negative cross price relationship)
• Substitutes: consumed instead. (positive cross price relationship)
• Normal Good: Increased demand when income rises
• Inferior Good: Decreased demand when income rises

Supply

• Comes from Seller
• Shifters: Production costs, Technology, Number of sellers, Government regulation, Future expectations
  • movement caused by change in price. Usually from changing demand
• Positive slope: producers supply where MR = MC. they supply more when they can charge more (greater marginal revenue)

Price Controls

Government set limits

• Binding: Interfere with equilibrium
• Price Ceiling: Maximum legal price. (Rent control)
  • Creates a shortage because $Q_D$ is higher at the lower price, and $Q_S$ is lower
• Price Floor: Minimum legal price. (Agriculture Support)
  • Creates a surplus because $Q_S$ is higher at the higher price, and $Q_D$ is lower
• Binding: Controls that affect equilibrium

Elasticity

How much does quantity respond to price change

• Price Elasticity:
  • Percent Method: $\mathrm{\Delta }Q\cdot P_1$ / $\mathrm{\Delta }P\cdot Q_1$
  • Midpoint Method: $\mathrm{\Delta }Q\cdot {\mu }_P$ / $\mathrm{\Delta }P\cdot {\mu }_Q$
• Elastic: |Ed| > 1 (responsive to price changes)
• Inelastic: |Ed| < 1 (less responsive to price changes)
• Income Elasticity: Distinguishes normal from inferior goods (replace price with Income)
  • Positive = Normal good. Negative = Inferior good
• Cross-Price Elasticity ($E_{xy}$): Determines substitutes vs. complements
  • Positive = Substitute. Negative = Compliment. |$E_{xy}$| > 1 (strong correlation)
• Elasticity is not determined by the graph, but by where on the graph you are

Welfare Economics

• Consumer Surplus: $Received-Minimum$. Area below demand curve, above price
• Producer Surplus: $Maximum-Paid$. Area above supply curve, below price
• Total Surplus: $S_C+S_P$
• Equilibrium maximizes total surplus (allocative efficiency)

Taxation

• Creates wedge between price paid by buyers and received by sellers
• Tax Burden: Split based on relative elasticities. More elasticity = greater burden
  
• Deadweight Loss: Efficiency loss from taxation
• Tax Revenue = Tax × Quantity (after tax)

3. Theory of Consumer Choice (5-10% of exam)

Utility Theory

• Total Utility: Total satisfaction from a given quantity (Parabolic)
  • Total utility maximized when $MU=0$ (x-intercept)
• Marginal Utility: Additional satisfaction from one more unit (Usually linear in examples)
• Diminishing Marginal Utility: MU decreases as consumption increases, even into negatives

Consumer Optimization

• Budget Constraint Curve: Shows all affordable consumption combinations
• Equimarginal principle (Utility Maximization Rule): $M{U}_a/P_a=M{U}_b/P_b$
• Consumer equilibrium: where budget is fully spent and the equimarginal principle is met
• The Consumer Demand Curve: comes from the optimal bundle at each price
• Market Demand Curve: the sum of all consumer demand curves

(Continue From Here) Income and Substitution Effects

• Income Effect: Change in consumption due to change in purchasing power
• Substitution Effect: Change in consumption due to relative price changes
• Both effects work together when prices change
• Help explain downward-sloping demand curves

4. Production and Costs (10-15% of exam)

Production Functions

• Short Run: At least one fixed input (usually capital)
• Long Run: All inputs variable
• Total Product: Maximum output from given inputs
• Marginal Product: Additional output from one more input unit
• Diminishing Returns: MP eventually decreases as input increases

Cost Concepts

• Fixed Costs (FC): Costs that don't change with output
• Variable Costs (VC): Costs that change with output
• Total Cost (TC): FC + VC
• Marginal Cost (MC): ΔTC/ΔQ
• Average Costs: AFC = FC/Q, AVC = VC/Q + ATC = TC/Q

Cost Curve Relationships

• MC intersects AVC and ATC at their minimum points
• When MC < ATC, ATC is falling
• When MC > ATC, ATC is rising
• AFC always decreases as output increases

Long-Run Costs

• Economies of Scale: ATC decreases as output increases
• Constant Returns to Scale: ATC remains constant
• Diseconomies of Scale: ATC increases as output increases

5. Firm Behavior and Market Structure (25-33% of exam)

Profit Maximization

• Economic Profit: Total Revenue - Total Economic Costs
• Accounting vs. Economic Profit: Economic includes opportunity costs
• Profit Maximization Rule: Produce where $MR=MC$
• Shutdown Rule: Continue if $MR>AVC$ (short run)

Perfect Competition

Characteristics:

• Many buyers and sellers
• Identical products
• Free entry and exit
• Perfect information

Behavior:

• Firms are price takers (P = MR)
• Short run: Can earn profits or losses
  • Will incur losses if $ATC>P$
• Long run: Zero economic profit $P=ATC$
• Allocatively efficient when $P=MC$

Monopoly

Characteristics:

• Single seller
• Barriers to entry
• Price setter

Behavior:

• Profit maximization: MR = MC, charge price from demand curve
• P > MC (allocatively inefficient)
• Creates deadweight loss
• Can earn long-run economic profits

Sources of Monopoly Power:

• Resource ownership
• Government-created monopolies
• Natural monopolies

Oligopoly

Characteristics:

• Few sellers
• Interdependent decision making
• Barriers to entry

Game Theory:

• Nash Equilibrium: Each player's strategy is optimal given others' strategies
• Dominant Strategy: Best choice regardless of what others do
• Tension between cooperation and self-interest
• Oligopolies will tend toward market equilibrium

Monopolistic Competition

Characteristics:

• Many sellers
• Differentiated products
• Free entry and exit

Behavior:

• Short run: Like monopoly (can earn profits)
• Long run: Like perfect competition (zero economic profit)
  • producing where MR=MC, price will eventually = ATC, due to firms entering and exiting
  • reduced market share can be viewed as a decrease in supply
• P > MC (some inefficiency)
• Excess capacity in long run

6. Factor Markets (6-12% of exam)

Derived Demand

• Input demand derives from output demand
• Marginal Revenue Product (MRP): MR × MP
• Value of Marginal Product (VMP): P × MP (in perfect competition)
• Firm hires inputs where MRP = input price

Labor Markets

• Labor Demand: Determined by MRP of labor
• Labor Supply: Determined by opportunity cost of time
• Equilibrium Wage: Where labor supply = labor demand
• Marginal Factor Cost (MFC): Cost of hiring one more worker

Factors Affecting Factor Demand

• Output price changes
• Productivity changes
• Prices of other inputs
• Technology changes

7. Market Failure and Role of Government (8-14% of exam)

Externalities

• Positive Externalities: Benefits to third parties (education, R&D)
• Negative Externalities: Costs to third parties (pollution)
• Private Value vs. Social Value: Market failures occur when they differ
• Solutions: Taxes, subsidies, regulations, property rights
• Market Efficiency: (allocative efficiency) occurs when resources are allocated to their highest-valued uses, maximizing total social welfare.

Types of Goods

• Private Goods: Food
• Club Goods: Software
• Common Resources: Fish in a pond
• Public Goods: Infrastructure
• Free Rider Problem: People use without paying
• Government provision necessary

Income Distribution

• Income Inequality: Uneven distribution of income across population
• Lorenz Curve: Graphical representation showing cumulative percentage of income earned by cumulative percentage of population
  • Perfect equality = 45-degree line
  • Greater curve from line = more inequality
• Gini Coefficient: Numerical measure of inequality (0 = perfect equality, 1 = perfect inequality)
  • Calculated as area between Lorenz curve and line of equality
• Sources of Income Inequality:
  • Education and skill differences
  • Discrimination (gender, racial, age)
  • Market power and monopoly rents
  • Technological change favoring skilled workers
  • Globalization effects
  • Inheritance and wealth concentration
  • Labor market institutions (unions, minimum wage)

Antitrust and Regulation

• Antitrust Laws: Promote competition, prevent monopolies
• Regulation: Government control of natural monopolies
• Deregulation: Removing government controls to increase competition

Formulas

Elasticity

• Price Elasticity of Demand:

  $$E_d=\frac{\mathrm{\%}\mathrm{\Delta }{Q}_d}{\mathrm{\%}\mathrm{\Delta }P}$$

• $E>1$ = Elastic

• Cross-Price Elasticity:

  $$E_{xy}=\frac{\mathrm{\Delta }Q\cdot {\mu }_P}{\mathrm{\Delta }P\cdot {\mu }_Q}$$
  • Positive = Substitute
  • Negative = Compliment,

• $|E_{xy}|>1$ = Strong relationship (elastic)

• Income Elasticity:

  $$E_y=\frac{\mathrm{\Delta }Q\cdot {\mu }_I}{\mathrm{\Delta }I\cdot {\mu }_Q}$$
  • Positive = Normal
  • Negative = Inferior

Costs and Production

• Opportunity Cost:

  $$\text{Opportunity Cost}=\frac{\text{Other}}{\text{Made}}$$

• Marginal Product:

  $$MP=\frac{\mathrm{\Delta }\text{Output}}{\mathrm{\Delta }\text{Input}}$$

• Marginal Cost:

  $$MC=\frac{\mathrm{\Delta }TC}{\mathrm{\Delta }Q}$$

• Profit:

  $$\text{Profit}=TR-TC=(P-ATC)\times Q$$

Consumer Theory

• Utility Maximization:

  $$\frac{M{U}_x}{P_x}=\frac{M{U}_y}{P_y}$$

• Budget Constraint Slope:

  $$\text{Slope}=-\frac{P_x}{P_y}$$

• Marginal Rate of Substitution:

  $$MR{S}_{xy}=\frac{M{U}_x}{M{U}_y}$$

Market Structure

• Profit Maximization:

  $$MR=MC$$

• Perfect Competition:

  $$P=MR=MC$$

• Monopoly:

  $$MR<P\text{and}\text{produce where }MR=MC$$

Factor Markets

• MRP:

  $$MRP=MR\times MP$$

• Labor Demand:

  $$MRP=\text{Wage}$$

Exam

Notes Post-Exam

Write Before Starting Test

• Types of goods
• Elasticity (midpoint)
• Profit Max
• Labor Max
• Consumer Max

Problem Topics

close notes while taking practice tests to get the most out of practice
Practice test 1 (61/80)

• Tax burden
• Marginal Rate of Substitution
• Diminishing Returns start when MP starts to fall
• Opportunity Cost vs Economic Cost aka Total Opportunity Cost (Petersons 1-43)
• Economic Profit (Petersons 1-45 is asking for the wrong thing)
• Monopoly Profit-Max: Output where MR=MC, Price = Demand Curve
• Monopolistic Competition
• Cartel vs Oligopoly
• Profit Max when hiring (apples to apples)
  Practice Test 2
• Marginal rate of substitution
• 27 does not include question - if he spends 32 hours writing what is his total revenue?
• 55 and 56 have no graph labels: A is demand, B is marginal revenue, C is Marginal Cost, D is Average Total Cost, Total Revenue = $P_3$ and Total Cost = $P_0$
• ChatGPT says the answer to 48 is wrong

High-Weight Topics

• Firm Behavior and Market Structure (25-33%)
• Supply and Demand (15-20%)
• Basic Economic Concepts (10-16%)

Key Concepts to Master

• Profit maximization across all market structures
• Elasticity calculations and applications
• Consumer optimization
• Cost relationships and curves
• Market efficiency and deadweight loss

Graph Analysis Skills

• Supply and demand shifts vs. movements
• Cost curves and their relationships
• Consumer choice (budget lines and indifference curves)
• Market structures and their outcomes

Common Question Types

• Definition and application questions
• Graph interpretation
• Calculation problems (elasticity, costs, profit)
• Comparative analysis between market structures
• Policy analysis (taxes, regulations, externalities)