Chapter 1: The Scope and Method of Economics

What is Economics?

Economics is the study of how individuals, firms, and societies make choices regarding the allocation of limited resources. It fundamentally addresses the problem of scarcity, which refers to the limited availability of resources.

• Scarcity: A condition where resources are insufficient to satisfy all wants.

• Microeconomics: Focuses on individual decision-making, firm behavior, and market interactions.

• Macroeconomics: Deals with aggregate economic phenomena, such as government policy, inflation, and GDP (not covered in microeconomics).

• Examples of Scarce Goods: Water, cars, diamonds, celebrities (e.g., Beyoncé).

• Non-Scarce Good: Air (in most contexts).

• Poverty vs. Scarcity: Poverty is an income threshold below which basic needs cannot be met; scarcity is a broader concept.

Five Foundations of Economics

• Incentives: Motivations that influence behavior, both positive (rewards) and negative (penalties). Example: Grades motivate students to study.

• Tradeoffs: Choosing one option means giving up others. Example: The cost of a bomber could alternatively fund hospitals or highways.

• Opportunity Cost: The value of the next best alternative forgone. Example: Waiting in line for a TV means giving up time that could be spent working or with family.

• Marginal Thinking: Evaluating the benefit of one additional unit versus its cost. Example: Deciding whether to buy one more textbook.

• Trade: Specialization and exchange make all parties better off.

The Scientific Method in Economics

• Observe phenomena

• Develop hypotheses

• Construct models

• Test models via experiments or real-world data

• Verify, revise, or refute hypotheses

Ceteris Paribus: Holding all other variables constant to isolate effects.

Endogenous Variables: Variables controlled within the model.

Exogenous Variables: Variables outside the model.

Positive vs. Normative Analysis

• Positive Statements: Testable and verifiable (e.g., "Nintendo Switch sold more than PlayStation 4").

• Normative Statements: Opinions or value judgments (e.g., "Nintendo Switch has better games").

Chapter 2: Scarcity and Choice

Opportunity Cost

Opportunity cost is the highest valued alternative forgone to pursue an activity.

• Example: Choosing between bus and plane travel, factoring in monetary cost and time value.

• Formula: ; solve for to find the value of time where both options are equally attractive.

Production Possibility Frontier (PPF)

The PPF illustrates the maximum combinations of two goods that can be produced with fixed resources.

• Non-linear PPF: Increasing opportunity cost as more of one good is produced.

• Linear PPF: Constant opportunity cost.

• Investment in Capital: Shifts the PPF outward, enabling greater future production.

Comparative and Absolute Advantage

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

• Absolute Advantage: Ability to produce more output with the same resources.

• Specialization: Parties should specialize in goods where they have comparative advantage and trade for mutual benefit.

Example Table: Anna and Beth's Production Possibilities

Additional info: Anna has a comparative advantage in mowing lawns; Beth in washing dishes.

Chapter 3: Demand and Supply

Law of Demand

There is an inverse relationship between price and quantity demanded.

• If price increases, quantity demanded decreases.

• Movement along the demand curve: Change in price or quantity only (change in quantity demanded).

• Shift of the demand curve: Change in other factors (income, tastes, prices of related goods, expectations).

Law of Supply

There is a direct relationship between price and quantity supplied.

• If price increases, quantity supplied increases.

• Movement along the supply curve: Change in price or quantity only (change in quantity supplied).

• Shift of the supply curve: Change in input costs, technology, taxes/subsidies, expectations.

Market Equilibrium

Market equilibrium occurs where quantity supplied equals quantity demanded ().

• Invisible Hand: Market forces push prices toward equilibrium.

• If , price falls; if , price rises.

Example: Market for Roses

• Demand:

• Supply:

• Equilibrium: Set

Chapter 5: Elasticity

Price Elasticity of Demand

Measures the responsiveness of quantity demanded to a change in price.

• Formula:

• Determinants: Number of substitutes, proportion of budget, time horizon.

• Elastic: Large change in quantity for a given price change.

• Inelastic: Small change in quantity for a given price change.

Calculating Elasticity

• Percentage Formula:

• Midpoint Formula:

Types of Elasticity

• Perfectly Inelastic: (e.g., emergency care)

• Relatively Inelastic: (e.g., gas, electricity)

• Unitary Elastic:

• Relatively Elastic: (e.g., apples)

• Perfectly Elastic:

Income Elasticity of Demand

Measures how quantity demanded changes with income.

• Formula:

• Normal Good:

• Necessity:

• Luxury:

• Inferior Good:

Cross-Price Elasticity of Demand

Measures how the quantity demanded of one good responds to the price change of another good.

• Formula:

• Substitutes:

• Complements:

Price Elasticity of Supply

Measures the responsiveness of quantity supplied to a change in price.

• Formula:

• Perfectly Inelastic Supply: (e.g., oceanfront land)

• Relatively Inelastic Supply: (e.g., cellphone towers)

• Relatively Elastic Supply: (e.g., hot dog vendors)

Chapter 4: Demand and Supply Applications

Consumer and Producer Surplus

• Consumer Surplus (CS): Difference between willingness to pay and actual price paid.

• Producer Surplus (PS): Difference between price received and minimum price willing to sell.

• Total Surplus (TS):

Efficiency and Equity

• Efficient Outcome: Allocation maximizes total surplus; all buyers and sellers matched.

• Equity: Fair distribution of goods; sometimes considered by economists.

Taxes and Deadweight Loss

• Per-Unit Tax: Tax on each unit sold.

• Levy: Who is legally responsible for paying the tax.

• Incidence: Who actually bears the tax burden (depends on elasticity).

• Deadweight Loss (DWL): Lost surplus due to reduced economic activity from taxes.

• Tax Revenue: Added to total surplus:

Example Table: Tax Incidence Calculation

Additional info: The more inelastic side of the market bears a greater tax incidence.

Price Controls

• Price Ceiling: Legally imposed maximum price (e.g., rent control, emergency price gouging laws).

• Binding Price Ceiling: Below equilibrium price; causes shortages and potential black markets.

• Price Floor: Legally imposed minimum price (e.g., minimum wage).

• Example: Minimum wage is $7.25 federally; price ceiling for human organs is $0 (cannot legally buy/sell).

Example Table: Black Market Prices for Human Organs

Additional info: Price controls can lead to inefficiency, shortages, and illegal markets.