您在這裡

The Sources of Economic Growth

19 一月, 2016 - 17:17

Economic growth implies an outward shift in an economy’s production possibilities curve. Recall that when we draw such a curve, we assume that the quantity and quality of the economy’s factors of production and its technology are unchanged. Changing these will shift the curve. Anything that increases the quantity or quality of the factors of production available to the economy or that improves the technology available to the economy contributes to economic growth.

Consider, for example, the dramatic gains in human capital that have occurred in the United States since the beginning of the past century. In 1900, about 3.5% of U.S. workers had completed a high school education. By 2006, that percentage rose almost to 92. Fewer than 1% of the workers in 1900 had graduated from college; as late as 1940 only 3.5% had graduated from college. By 2006, nearly 32% had graduated from college. In addition to being better educated, today’s workers have received more and better training on the job. They bring far more economically useful knowledge and skills to their work than did workers a century ago.

Moreover, the technological changes that have occurred within the past 100 years have greatly reduced the time and effort required to produce most goods and services. Automated production has become commonplace. Innovations in transportation (automobiles, trucks, and airplanes) have made the movement of goods and people cheaper and faster. A dizzying array of new materials is available for manufacturing. And the development of modern information technology—including computers, software, and communications equipment—that seemed to proceed at breathtaking pace especially during the final years of the last century and continuing to the present has transformed the way we live and work.

Look again at the technological changes of the last few years described in the Case in Point on advances in technology. Those examples of technological progress through applications of computer technology—from new ways of mapping oil deposits to new methods of milking cows—helped propel the United States and other economies to dramatic gains in the ability to produce goods and services. They have helped shift the countries’ production possibilities curve outward. They have helped fuel economic growth.

Table 2.1 summarizes the factors that have contributed to U.S. economic growth in the past half century. When looking at the period of 1948–2002 as a whole we see that about 60% of economic growth stems from increases in the quantities of capital and labor and 40% from increases in the qualities of the factors of production and improvements in technology. In the most recent period, 1995–2002, however, these percentages are essentially reversed, with a little less than 30% explained by increases in quantities of the factors of production and a whopping 70% explained by improvements in factor quality and technology.

Table 2.1 Sources of U.S. Economic Growth, 1948–2002

Year

Percentage contribution to growth

Period growth rate

Years 1948–2002

3.46%

Increase in quantity of labor

21%

 

Increase in quantity of capital

41%

 

Increase in quality of labor

10%

 

Increase in quality of capital

20%

 

Improved technology

25%

 

Years 1948–1973

3.99%

Increase in quantity of labor

15%

 

Increase in quantity of capital

44%

 

Increase in quality of labor

11%

 

Increase in quality of capital

5%

 

Improved technology

25%

 

Years 1973–1989

2.97%

Increase in quantity of labor

31%

 

Increase in quantity of capital

39%

 

Increase in quality of labor

7%

 

Increase in quality of capital

12%

 

Improved technology

10%

 

Years 1989–1995

2.43%

Increase in quantity of labor

26%

 

Increase in quantity of capital

33%

 

Increase in quality of labor

15%

 

Increase in quality of capital

17%

 

Improved technology

11%

 

Years 1995–2002

3.59%

Increase in quantity of labor

19%

 

Increase in quantity of capital

8%

 

Increase in quality of labor

5%

 

Increase in quality of capital

47%

 

Improved technology

20%

 
 

Total output during the period shown increased sixfold. The chart shows the percentage of this increase accounted for by increases in the quantity of labor and of capital and by increases in the quality of labor and of capital and improvements in technology. In the 1995–2002 period, the incorporation of information technology led to improvements in the quality of capital and technology that greatly contributed to growth.

Source: Based on Dale W. Jorgenson, “Accounting for Growth in the Information Age,” Handbook of Economic Growth, Phillipe Aghion and Steven Durlauf, eds. Amsterdam: North Holland, 2005.

Another way of looking at these data for the most recent period is to notice that the increase in the rate of economic growth between the 1989 to 1995 period and the 1995 to 2002 period of more than one percentage point per year is largely explained by better-quality capital and better technology. The study by economist Dale Jorgenson on which the data shown in Table 2.1 are derived notes that these two main contributors to higher economic growth can be largely attributed to the development of information technology and its incorporation in the workplace.