Core Principles and Models in Macroeconomics: Study Notes

Chapter 1: Economics – Foundations and Models

Key Economic Ideas

• People are rational: Individuals and firms make decisions to maximize their benefit, weighing costs and benefits. Example: Apple sets iPhone prices to maximize profit, not randomly.

• People respond to economic incentives: Changes in incentives alter behavior. Example: DNA databases for felons increase the likelihood of catching repeat offenders, deterring crime.

• Optimal decisions are made at the margin: Most choices involve small adjustments, considering the additional benefit versus additional cost. Example: Deciding whether to study an extra hour or watch TV.

Scarcity and Trade-offs

• Scarcity: Unlimited wants exceed limited resources, forcing choices.

• Trade-off: Producing more of one good means producing less of another due to scarcity.

Efficiency vs. Equality

• Efficiency: Maximizing total output (the economic "pie").

• Equality: Fair distribution of output among individuals.

Types of Economies

• Traditional: Based on customs and beliefs.

• Command (Central): Government makes all economic decisions.

• Market: Decisions made by households and firms through supply and demand.

• Mixed: Combination of market forces and government intervention (e.g., U.S. economy).

Positive vs. Normative Analysis

• Positive analysis: Describes "what is" (objective, testable).

• Normative analysis: Describes "what ought to be" (subjective, value-based).

Role of Economic Models

• Models simplify reality to analyze economic issues, based on rational behavior and maximizing well-being.

Microeconomics vs. Macroeconomics

• Microeconomics: Study of individual households, firms, and markets.

• Macroeconomics: Study of the economy as a whole (inflation, unemployment, growth).

Chapter 2: Trade-offs, Comparative Advantage, and the Market System

Production Possibilities Frontier (PPF)

• Definition: Curve showing maximum attainable combinations of two goods with available resources and technology.

• Efficiency: Points on the PPF are efficient; inside are inefficient; outside are infeasible.

Opportunity Cost

• Producing more of one good requires giving up some of another. Example: Funding space exploration may mean less funding for cancer research.

Economic Growth

• Ability to increase production of goods and services, shifting the PPF outward.

Comparative vs. Absolute Advantage

• Comparative advantage: Lower opportunity cost in producing a good.

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

• Trade is based on comparative advantage, not absolute advantage.

Gains from Trade and Specialization

• Specialization and trade allow higher consumption and efficiency.

Market System and Circular Flow Diagram

• Market: Group of buyers and sellers for a good/service.

• Households: Provide factors of production (labor, capital, natural resources, entrepreneurship).

• Firms: Purchase factors, produce goods/services.

Flow	Description
1. Households → Firms	Provide factors of production
2. Firms → Households	Provide goods and services
3. Firms → Households	Pay for factors of production
4. Households → Firms	Pay for goods and services

Chapter 3: Where Prices Come From – Demand and Supply

Market Types

• Perfectly competitive market: Many buyers/sellers, identical products, no barriers to entry.

Law of Demand

• As price falls, quantity demanded rises (ceteris paribus); as price rises, quantity demanded falls.

• Substitution effect: Consumers switch to cheaper alternatives.

• Income effect: Lower prices increase purchasing power.

Law of Supply

• As price rises, quantity supplied rises; as price falls, quantity supplied falls (holding other factors constant).

Supply and Demand Curves vs. Quantity Supplied/Demanded

• Curves show the relationship for all prices; quantity supplied/demanded is at a specific price.

Factors Shifting Demand

• Income (normal vs. inferior goods)

• Prices of related goods (substitutes and complements)

Normal vs. Inferior Goods

• Normal good: Demand increases as income rises (e.g., new clothes).

• Inferior good: Demand increases as income falls (e.g., instant noodles).

Equilibrium

• Where quantity supplied equals quantity demanded; determines market price and quantity.

Shifts and Double Shifts

• Shifts in demand or supply curves change equilibrium price and quantity; double shifts require analyzing both effects.

Supply and Demand Schedules

• Tables showing price-quantity relationships for supply or demand.

Chapter 8: Measuring Total Production and Income (GDP)

Gross Domestic Product (GDP)

• Definition: Market value of all final goods and services produced within a country in a period.

• Only final goods are counted to avoid double counting.

GDP and Income

• Total production equals total income; every dollar spent becomes income for someone (wages, rent, interest, profit).

Components of GDP

Component	Description
Consumption (C)	Household spending on goods/services (durable, nondurable, services)
Investment (I)	Spending on capital goods, inventories, and new housing
Government Purchases (G)	Government spending on goods/services (excludes transfer payments)
Net Exports (NX)	Exports minus imports

Shortcomings of GDP

• Excludes household production and underground economy.

Calculating GDP

• Nominal GDP: $\text{Nominal GDP} = \sum (\text{Quantity in current year} \times \text{Price in current year})$

• Real GDP: $\text{Real GDP} = \sum (\text{Quantity in current year} \times \text{Price in base year})$

• GDP Deflator: $\text{GDP Deflator} = \frac{\text{Nominal GDP}}{\text{Real GDP}} \times 100$

• Inflation Rate: $\text{Inflation Rate} = \frac{\text{Price Level this year} - \text{Price Level last year}}{\text{Price Level last year}} \times 100$

Other Measures

• Gross National Product (GNP): Production by a nation's citizens, including abroad.

• National Income: $\text{GDP} - \text{Depreciation}$

• Personal Income: National income minus retained earnings plus government transfers and interest.

• Disposable Personal Income: Income available after taxes.

Chapter 9: Unemployment and Inflation

Labor Force Segmentation

• Employed: Currently working or temporarily absent.

• Unemployed: Not working, available, and actively seeking work.

• Not in labor force: Not working or seeking work.

Measuring Unemployment

• Household Survey: Measures labor force status via self-report.

• Establishment Survey: Measures payroll jobs, excludes self-employed.

Measure	Formula
Unemployment Rate	$\frac{\text{Unemployed}}{\text{Labor Force}} \times 100$
Labor Force Participation Rate	$\frac{\text{Labor Force}}{\text{Working-age Population}} \times 100$
Employment-Population Ratio	$\frac{\text{Employed}}{\text{Working-age Population}} \times 100$

Discouraged Workers

• Available for work but not seeking due to lack of opportunities; not counted as unemployed.

Types of Unemployment

• Frictional: Short-term, normal job search or seasonal.

• Structural: Mismatch of skills and jobs, often long-term.

• Cyclical: Due to economic downturns (recessions).

Full Employment and Natural Rate

• Full employment: Only frictional and structural unemployment exist.

• Natural Rate of Unemployment: Normal rate at full employment (about 4-5% in the U.S.).

Consumer Price Index (CPI) and Inflation

• Steps to calculate CPI:

  1. Choose a market basket of goods.

  2. Find cost in base year.

  3. Find cost in current year.

  4. Compute: $\text{CPI} = \frac{\text{Cost in current year}}{\text{Cost in base year}} \times 100$

• Inflation Rate: $\frac{\text{CPI this year} - \text{CPI last year}}{\text{CPI last year}} \times 100$

Indexation

• Automatic adjustment of payments for inflation (e.g., Social Security, wages).

Shortcomings of CPI

• Substitution bias, quality bias, new product bias, outlet bias; CPI may overstate inflation.

Nominal vs. Real Interest Rates

• Nominal interest rate: Stated rate, not adjusted for inflation.

• Real interest rate: $\text{Real Interest Rate} = \text{Nominal Interest Rate} - \text{Inflation Rate}$

Chapter 10: Economic Growth, the Financial System, and Business Cycles

Long-Run Economic Growth

• Measured by increases in real GDP per capita over time.

Growth Rate Calculations

• Annual Growth Rate: $\text{Growth Rate} = \frac{\text{Value this year} - \text{Value last year}}{\text{Value last year}} \times 100$

• Constant Growth Rule: $\text{Current GDP} = \text{Previous GDP} \times (1+g)^t$

• Rule of 70: $\text{Years to double} = \frac{70}{\text{Growth Rate (%)}}$

Determinants of Growth

• Labor productivity (output per hour), capital per worker, technological change, secure property rights.

Actual vs. Potential GDP

• Actual GDP: Current real GDP.

• Potential GDP: Output at normal capacity and employment.

Financial System

• Connects savers and borrowers via financial markets (stocks, bonds) and intermediaries (banks, mutual funds).

• Direct finance: Households buy securities directly from firms.

• Indirect finance: Households deposit in banks, which lend to firms.

Savings and Investment Identity (Closed Economy)

• From GDP: $Y = C + I + G$

• Rearranged: $I = Y - C - G$

• In a closed economy, savings equals investment ($S = I$).

Market for Loanable Funds

• Shows interaction of borrowers and lenders, determining real interest rate and quantity of funds loaned.

• Movements along the curve are due to interest rate changes; shifts are due to changes in saving or investment behavior.

Crowding Out

• Government borrowing increases demand for loanable funds, raising interest rates and reducing private investment.

Effects of Inflation

• Unexpected inflation reduces the real value of savings.

Chapter 16: Fiscal Policy

Definition and Tools

• Government use of spending and taxes to influence the economy.

• Tools: Government purchases and taxes.

Automatic Stabilizers vs. Discretionary Policy

• Automatic stabilizers: Built-in responses (e.g., unemployment benefits rise in recessions).

• Discretionary policy: Deliberate government actions (e.g., stimulus checks).

Expansionary vs. Contractionary Policy

• Expansionary: Increases spending or cuts taxes to boost economy (used in recessions).

• Contractionary: Decreases spending or raises taxes to cool economy (used to fight inflation).

Government Budget Deficits and Crowding Out

• Deficit: Spending exceeds tax revenue; government borrows, increasing demand for loanable funds and raising interest rates.

• Crowding out: Higher interest rates reduce private investment.

Multipliers

• Government Purchases Multiplier: $\frac{1}{1 - MPC}$

• Tax Multiplier: $\frac{-MPC}{1 - MPC}$

• Balanced Budget Multiplier: Even with balanced budget, economy expands due to multiplier effects.

Interaction with Monetary Policy

• Fiscal and monetary policy can be used together to stabilize the economy.

Chapter 17: Inflation, Unemployment, and Federal Reserve Policy

The Phillips Curve

• Shows short-run inverse relationship between inflation and unemployment.

• Short-run Phillips curve is downward sloping due to misjudged inflation by workers/firms.

• Long-run Phillips curve is vertical at the natural rate of unemployment (potential GDP).

Structural Relationships

• Stable relationships based on consumer and firm behavior, unchanged over time.

Natural Rate of Unemployment (NAIRU)

• Unemployment rate when economy is at potential GDP; also called Non-Accelerating Inflation Rate of Unemployment (NAIRU).

Shifts in the Phillips Curve

• Expectations of inflation can shift the short-run Phillips curve.

Real Wages and Inflation

• Inflation affects real wages; as inflation rises, real wages may fall if nominal wages do not keep up.

• Real Wage: $\text{Real Wage} = \frac{\text{Nominal Wage}}{\text{Price Level}}$