Introduction to Macroeconomics

What is Economics?

Economics is the study of how individuals, firms, and societies allocate scarce resources to satisfy unlimited wants. It involves analyzing choices and trade-offs due to scarcity.

• Scarcity: The fundamental economic problem of having limited resources to meet unlimited wants.

• Opportunity Cost: The value of the next best alternative forgone when making a decision.

• Example: Choosing to spend time studying economics instead of working a part-time job means the opportunity cost is the wage you could have earned.

Macroeconomics vs. Microeconomics

Economics is divided into two main branches:

• Microeconomics: Focuses on individual markets, firms, and consumers.

• Macroeconomics: Studies the economy as a whole, including aggregate measures like GDP, unemployment, and inflation.

Keynes and the Foundations of Macroeconomics

John Maynard Keynes is considered the founding figure of modern macroeconomics. He argued that aggregate demand determines overall economic activity and that government intervention can help stabilize the business cycle.

• Contribution: Developed theories explaining persistent unemployment and the need for fiscal and monetary policy.

The Business Cycle

The business cycle refers to the fluctuations in economic activity over time, typically measured by changes in real GDP.

• Phases: Expansion, peak, contraction (recession), trough.

Three Concerns of Macroeconomics

• Inflation: The general increase in prices over time.

• Unemployment: The share of the labor force without jobs but actively seeking work.

• Long-run Growth: The sustained upward trend in the economy's output over time.

• Phillips Curve: Shows the short-run trade-off between inflation and unemployment.

Circular Flow Diagram

The circular flow diagram illustrates the movement of goods, services, and money between households and firms in an economy.

• Households: Provide factors of production (labor, capital) and receive income.

• Firms: Produce goods and services and pay income to households.

Demand, Supply, and Market Equilibrium

Law of Demand and Demand Curve

The law of demand states that, ceteris paribus, as the price of a good increases, the quantity demanded decreases.

• Demand Curve: Downward sloping, showing the inverse relationship between price and quantity demanded.

• Movement Along the Demand Curve: Caused by a change in the price of the good itself.

• Shift of the Demand Curve: Caused by changes in determinants other than the good's price (e.g., income, tastes, prices of related goods, expectations).

• Determinants of Demand: Income/wealth, price of substitutes/complements, preferences/tastes, expectations.

Law of Supply and Supply Curve

The law of supply states that, ceteris paribus, as the price of a good increases, the quantity supplied increases.

• Supply Curve: Upward sloping, showing the direct relationship between price and quantity supplied.

• Movement Along the Supply Curve: Caused by a change in the price of the good itself.

• Shift of the Supply Curve: Caused by changes in determinants other than the good's price (e.g., input prices, technology, expectations).

• Determinants of Supply: Land, labor, capital (LLC), expectations.

Market Equilibrium, Excess Demand, and Excess Supply

• Market Equilibrium: Occurs where quantity demanded equals quantity supplied.

• Excess Demand (Shortage): Quantity demanded exceeds quantity supplied at a given price.

• Excess Supply (Surplus): Quantity supplied exceeds quantity demanded at a given price.

Measuring National Output and National Income

Gross Domestic Product (GDP)

GDP is the market value of all final goods and services produced within a country during a specific period.

• Included in GDP: Final goods and services, new production.

• Not Included: Used goods, intermediate goods, purely financial transactions (e.g., stocks, bonds).

• Example: A new car produced and sold in the current year is included; a used car resale is not.

GDP vs. GNP

• GDP (Gross Domestic Product): Measures output produced within a country's borders.

• GNP (Gross National Product): Measures output produced by a country's residents, regardless of location.

• Example: GM's car production in Mexico counts toward Mexico's GDP but the USA's GNP.

Methods of Measuring GDP

• Expenditure Approach: Sums total spending on final goods and services.

• Formula:

• Components: Consumption (C), Investment (I), Government Spending (G), Net Exports (NX = Exports - Imports).

• Income Approach: Sums all incomes earned in the production of goods and services.

• Formula:

• GDP = Final Sales + Change in Business Inventories

• Limitations: GDP does not account for non-market transactions, underground economy, or environmental degradation.

Nominal GDP vs. Real GDP

• Nominal GDP: Measured using current prices; not adjusted for inflation.

• Real GDP: Measured using constant base-year prices; adjusted for inflation.

• GDP Deflator: Measures the price level of all new, domestically produced, final goods and services in an economy.

• Formula:

• Interpreting GDP Deflator and Inflation Rate: The GDP deflator shows how much prices have changed since the base year. The inflation rate is the percentage change in the price level from one year to the next.

Unemployment, Inflation, and Long-Run Growth

Measuring Unemployment and Labor Force Participation

• Unemployment Rate:

• Labor Force Participation Rate:

• Definitions:

  • Employed: People currently working for pay.

  • Unemployed: People not working but actively seeking work.

  • Not in Labor Force: People not working and not seeking work (e.g., retirees, students).

• Discouraged Worker Effect: When people stop looking for work, they are no longer counted as unemployed, which can lower the unemployment rate but also reduce the labor force participation rate.

Types of Unemployment

• Frictional Unemployment: Short-term, occurs when people are between jobs or entering the labor force.

• Structural Unemployment: Long-term, caused by changes in the structure of the economy (e.g., technological change).

• Cyclical Unemployment: Caused by downturns in the business cycle.

Natural Rate of Unemployment and Full Employment

• Natural Rate of Unemployment (NRU): The sum of frictional and structural unemployment; the unemployment rate when the economy is at full employment.

• Full Employment: When cyclical unemployment is zero.

• Potential GDP: The level of output when the economy is at full employment.

• Relationship:

• Depending on the state of the economy, cyclical unemployment can be positive, negative, or zero.

Inflation

• Inflation: The sustained increase in the general price level.

• Measures of Inflation:

  • GDP Deflator: Reflects prices of all domestically produced goods and services.

  • Consumer Price Index (CPI): Measures the cost of a fixed basket of goods and services purchased by a typical consumer.

  • Formula for CPI:

  • Inflation Rate: (where and are price indices in two periods)

• Differences between GDP Deflator and CPI: The GDP deflator covers all goods and services produced domestically, while the CPI covers only goods and services bought by consumers.

• Real Interest Rate:

• Costs of Inflation:

  • Anticipated Inflation: Can be planned for; does not necessarily reduce purchasing power if incomes keep pace.

  • Unanticipated Inflation: Can redistribute income (e.g., borrowers benefit, lenders lose) and cause administrative costs (e.g., menu costs).

Long-Run Growth

Measures and Factors of Economic Growth

• Three Approaches:

  • Output Growth: Increase in total production.

  • Per-Capita Output Growth: Increase in output per person.

  • Labor Productivity Growth: Increase in output per worker or per hour worked.

• Factors for Output Growth:

  • Quality and Quantity of Factors of Production: Labor, capital, land, and technology.

  • Diminishing Returns: Without increases in capital, adding more labor yields progressively smaller increases in output.

Key Macroeconomic Formulas