1. Chapter 8
Economic Growth

2. 1. THE SIGNIFICANCE OF ECONOMIC GROWTH
Learning Objectives
Define economic growth and explain it using the production possibilities model and the concept of potential output.
State the rule of 72 and use it to show how even small differences in growth rates can have major effects on a country’s potential output over time.
Calculate the percentage rate of growth of output per capita.

3. 1.1 Defining Economic Growth

4. 1.2 The Rule of 72 and Differences in Growth Rates
Exponential growth occurs when a quantity grows at a given percentage rate.
The rule of 72 states that a variable’s approximate doubling time equals 72 divided by the growth rate, stated as a whole number.

5. 1.3 Growth in Output per Capita
Output per capita is real GDP per person.
EQUATION 1.1
Output per capita = real GDP N
EQUATION 1.2
% rate of growth of output per capita ≈
% rate of growth of output - % rate of growth of population

6. Differences in Growth Rates: 3.5% growth vs. 2.4% growth
Third doubling
Real GDP, 3.5 percent growth
Second doubling
First doubling
Second doubling
First doubling
Real GDP, 2.4 percent growth

7. 2. GROWTH AND THE LONG-RUN AGGREGATE SUPPLY CURVE
Learning Objectives
Explain and illustrate graphically the concept of the aggregate production function. Explain how its shape relates to the concept of diminishing marginal returns.
Derive the long-run aggregate supply curve from the model of the labor market and the aggregate production function.
Explain how the long-run aggregate supply curve shifts in responses to shifts in the aggregate production function or to shifts in the demand for or supply of labor.

8. Economic Growth and the Long-Run Aggregate Supply Curve
LRAS1
LRAS2
LRAS3
LRAS4 Y1 Y2 Y3 Y4

9. 2.1 The Aggregate Production Function.
The Aggregate production function is a function that relates the total output of an economy to the total amount of labor employed in the economy, all other determinants of production (capital, natural resources, and technology) being unchanged.
Diminishing marginal returns refers to a situation that occurs when additional units of a variable factor add less and less to total output, given constant quantities of other factors.

10. Productivity = Quantity/Labor
2.2 The Aggregate Production Function, the Market for Labor, and Long-Run Aggregate Supply
Productivity is the amount of output per worker
Productivity = Quantity/Labor C PF B A

11. Deriving the Long-Run Aggregate Supply
LRAS S1 PF YP w1 D1 L1 L1 YP

12. Shift in the Aggregate Production Function and the Long-Run Aggregate Supply Curve
PF2
LRAS1
LRAS2 S1 Y2
PF1 w2 Y1 w1 D2 D1 L1 L2 L1 L2 Y1 Y2

13. Increase in the Supply of Labor and the Long-Run Aggregate Supply Curve
LRAS1
LRAS2 S1 S2
PF1 Y2 w1 Y1 w2 D1 L1 L2 L1 L2 Y1 Y2

14. 3. DETERMINANTS OF ECONOMIC GROWTH
Learning Objectives
Discuss the sources of economic growth.
Discuss possible reasons why countries grow at different rates.

15. 3.1 The Sources of Economic Growth
Economic growth occurs as an outward shift in the production possibilities curve and as a shift to the right in long run aggregate supply.
Sources of growth in the U.S. in the 20th century
Increased labor and physical capital
Improved factor of production quality and technology
Increased savings

16. 3.2 Explaining Recent Disparities in Growth Rates
There has been a growing disparity in the rates of economic growth in industrialized countries in the last decade which may reflect various differences in economic structures and policies.
For OECD_24 countries, standard deviation of GDP per capita growth increased in the last two decades of the 20th century
Standard deviation was 0.74
Standard deviation was 1.17
If we just look at the last 4 years of the 20th century we see an even larger standard deviation.
Standard deviation was 1.37