Introduction to Macroeconomics

Assumptions of Economic Models

• Economic models are simplified representations of reality used to analyze economic issues and predict outcomes.

• Common assumptions include rational behavior, ceteris paribus (holding other things constant), and scarcity of resources.

• Assumptions help focus on key variables but may limit real-world applicability.

Scarcity and Opportunity Cost

• Scarcity means resources are limited relative to wants.

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

• Scarcity forces individuals and societies to make choices, leading to opportunity costs.

Pitfalls in Economic Analysis

• Ignoring secondary effects, confusing correlation with causation, and failing to consider ceteris paribus can lead to incorrect conclusions.

Positive vs. Normative Analysis

• Positive analysis deals with objective, testable statements about "what is."

• Normative analysis involves subjective judgments about "what ought to be."

Microeconomics vs. Macroeconomics

• Microeconomics studies individual markets and agents.

• Macroeconomics examines the economy as a whole, including aggregate output, employment, and inflation.

Introductory Economic Models

Types of Economic Systems

• Free market economy: Decisions are made by individuals and firms with minimal government intervention.

• Centrally planned economy: The government makes most economic decisions.

• Mixed economy: Combines elements of both market and planned economies.

Production Possibilities Curve (PPC)

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

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

• PPC shifts outward with economic growth (more resources/technology), inward with resource loss.

• A bowed-out PPC reflects increasing opportunity costs.

Productive vs. Allocative Efficiency

• Productive efficiency: Producing goods at the lowest possible cost (on the PPC).

• Allocative efficiency: Producing the mix of goods most desired by society.

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 is based on comparative, not absolute, advantage.

Private Property Rights and Market Incentives

• Private property rights encourage investment, innovation, and efficient resource use.

• Free markets reward producers who meet consumer preferences, leading to higher quality, variety, and lower prices.

Adam Smith’s Invisible Hand

• The "invisible hand" describes how self-interested actions can lead to positive social outcomes.

• I, Pencil illustrates the complexity and coordination of market economies.

Supply and Demand

Demand

• Law of demand: As price falls, quantity demanded rises (ceteris paribus).

• Demand curve: Downward sloping; can be drawn from a demand schedule.

• Movement along the curve: Caused by price changes.

• Shifts in demand: Caused by changes in income, tastes, prices of related goods, expectations, and number of buyers.

Supply

• Law of supply: As price rises, quantity supplied rises (ceteris paribus).

• Supply curve: Upward sloping; can be drawn from a supply schedule.

• Movement along the curve: Caused by price changes.

• Shifts in supply: Caused by input prices, technology, expectations, number of sellers, and taxes/subsidies.

Market Equilibrium

• Equilibrium: Where supply and demand curves intersect; determines market price and quantity.

• Price above equilibrium: Surplus; price below equilibrium: Shortage.

• Shifts in supply or demand change equilibrium price and quantity.

Consumer and Producer Surplus; Price Ceilings and Price Floors

Consumer and Producer Surplus

• Consumer surplus: Area below the demand curve and above the price.

• Producer surplus: Area above the supply curve and below the price.

• Total economic surplus is maximized in competitive equilibrium.

Price Floors and Ceilings

• Price floor: Minimum legal price (e.g., minimum wage); can create surpluses.

• Price ceiling: Maximum legal price (e.g., rent control); can create shortages.

• Both can lead to deadweight loss (loss of total surplus).

Taxes and Tax Incidence

• Taxes shift supply or demand curves, reducing quantity traded.

• Tax incidence: The division of the tax burden between buyers and sellers depends on elasticity.

• Deadweight loss, government revenue, and changes in surplus can be calculated from graphs.

Measuring National Output and Income (GDP)

GDP Calculation Methods

• Expenditure approach:

• Output (value-added) approach: Sum of value added at each production stage.

• Income approach: Sum of incomes earned in production.

GDP and the Business Cycle

• GDP tracks expansions and recessions in the business cycle.

• Final goods are included in GDP; intermediate goods are not, to avoid double counting.

• GDP is an imperfect measure of well-being and does not capture all production (e.g., household work, black market).

Real vs. Nominal GDP and Related Measures

• Nominal GDP: Measured in current prices.

• Real GDP: Adjusted for inflation (base year prices).

• GDP Deflator:

• GDP Growth Rate:

Unemployment and Inflation

Types of Unemployment

• Frictional: Short-term, between jobs.

• Structural: Mismatch between skills and jobs.

• Cyclical: Due to economic downturns (most concerning for macroeconomists).

Measuring Unemployment and Labor Force Participation

• Unemployment rate:

• Labor Force Participation Rate (LFPR):

• Discouraged workers are not counted as unemployed, lowering the unemployment rate and LFPR.

Inflation Measurement and Effects

• Consumer Price Index (CPI): Measures average price changes for a basket of goods.

• Inflation rate:

• Convert nominal to real values:

• Inflation erodes purchasing power; deflation can lead to economic stagnation.

• Unexpected inflation benefits borrowers, harms lenders.

Aggregate Expenditures Model

Consumption and Investment Functions

• Consumption function: where is the marginal propensity to consume (MPC).

• MPC: Change in consumption from an additional dollar of income.

• MPS: Marginal propensity to save; .

• Investment function: Shows planned investment at different income levels.

Net Exports and Equilibrium

• Net exports: ; affected by exchange rates, foreign income, and domestic income.

• Unplanned inventory changes signal disequilibrium; equilibrium occurs when .

• Multiplier:

Policy Applications

• The model explains government responses to recessions, such as increased spending to boost aggregate demand.

Aggregate Demand and Aggregate Supply Analysis

Aggregate Demand (AD)

• AD curve shows total spending at different price levels.

• Movements along AD: Caused by price level changes; shifts: Caused by changes in C, I, G, or NX.

Aggregate Supply (AS)

• Long Run AS (LRAS): Vertical at potential output; shifts with changes in resources, technology.

• Short Run AS (SRAS): Upward sloping due to sticky prices/wages; shifts with input costs, expectations.

Short-Run vs. Long-Run Adjustments

• SR: Firms increase output when prices rise; LR: Output returns to potential as prices/wages adjust.

• Shocks (AD or supply) affect output and prices differently in SR and LR.

The Financial System, Money, Banking, and Monetary Policy

Money and Its Functions

• Money: Medium of exchange, unit of account, store of value.

• Commodity money: Has intrinsic value (e.g., gold); fiat money: Value by government decree.

• Barter requires double coincidence of wants; money simplifies transactions.

The Federal Reserve and Money Supply

• The Fed was created to prevent bank panics and stabilize the financial system.

• M1: Currency + checkable deposits; M2: M1 + savings deposits, small time deposits, money market funds.

• Bank run: Many withdraw deposits; bank panic: Multiple banks affected; deposit insurance prevents panics.

• Fractional reserve banking: Banks keep a fraction of deposits as reserves.

• Discount rate: Rate Fed charges banks; federal funds rate: Rate banks charge each other.

• The Fed is independent to insulate policy from political pressures.

Federal Reserve Structure and Tools

• FOMC: Federal Open Market Committee; sets monetary policy via open market operations (buying/selling government securities).

• Other tools: Discount rate, reserve requirements, interest on reserves.

• Newer tools: Quantitative easing, lending facilities (used in 2007-2009 recession).

• Mortgage-backed securities played a role in the financial crisis.

Money Creation and the Money Multiplier

• Banks create money by lending excess reserves.

• Required reserves: Minimum reserves set by the Fed; excess reserves: Reserves above the minimum.

• Simple Deposit Multiplier:

Monetary Policy and the Quantity Theory of Money

• Fed uses tools to influence money supply and interest rates to achieve goals (stable prices, full employment).

• Expansionary policy: Increases money supply, lowers rates; contractionary: Opposite.

• Interest rates affect aggregate demand (investment, consumption).

• Quantity Theory of Money: ; suggests money supply growth should match output growth.

Fiscal Policy

Policymakers and Tools

• Congress and the President set fiscal policy.

• Tools: Government spending, taxation.

• Expansionary policy: Increases spending or cuts taxes; contractionary: Opposite.

Effects and Concerns

• Fiscal policy shifts AD curve.

• Concerns: Policy lags, crowding out (government borrowing raises interest rates), budget deficits and debt.

• Automatic stabilizers (e.g., unemployment insurance) help smooth the business cycle.

• Social Security and Medicare face long-term funding challenges.

Supply-Side Economics and the Laffer Curve

• Supply-siders focus on incentives for production (AS), not just demand.

• Laffer curve: Shows relationship between tax rates and tax revenue; suggests high rates can reduce revenue.

Inflation, Unemployment, and Macroeconomic Schools of Thought

The Phillips Curve

• Short-run: Inverse relationship between inflation and unemployment.

• Long-run: No tradeoff; curve is vertical at the natural rate of unemployment.

• Unanticipated inflation can temporarily lower unemployment.

• Expectations shift the Phillips curve.

Rules vs. Discretion in Policy

• Rules: Fixed policy rules (e.g., Monetarists favor steady money growth).

• Discretion: Policymakers adjust as needed (Keynesians).

• Taylor Rule: Formula for setting interest rates based on inflation and output gaps.

Keynes vs. Hayek

• Keynes: Booms/busts from demand shocks; government should intervene in recessions.

• Hayek: Booms/busts from misallocated resources; government intervention can worsen cycles.

Economic Growth

Measuring Growth and the Rule of 70

• Growth measured by increases in real GDP per capita.

• Rule of 70: Years to double =

Sources and Patterns of Growth

• Growth fueled by capital, labor, technology, and institutions.

• Some countries catch up due to investment, education, and openness; others lag due to poor institutions or policies.

• Globalization and Economic Freedom Index (EFW) are linked to higher growth rates.