Economic growth and economic development 219

Introduction to Modern Economic Growth
effect on changes in life expectancy prior to this date (i.e., before the key interventions). This suggests that the large increases in life expectancy experience by many
countries after 1940 were in fact related to the global health interventions.
Perhaps not surprisingly, Acemoglu and Johnson (2006) find that predicted mortality and the changes in life expectancy that it causes have a fairly large effect on
population; a 1% increase in life expectancy is related to an approximately 1.3-1.8%
increase in population. However, there is no evidence of a positive effect on GDP per
capita. This is depicted in Figure 4.16, shows no convergence in income per capita
between initially-poor, initially-middle-income and initially-rich countries. Similarly, there appears to be no evidence of an increase in human capital investments
associated with improvements in life expectancy.

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10

9

8

7

6

5
1930

1940

1950

Initially Poor

1960

1970

Initially Middle Income

1980

1990

2000

Initially Rich

Figure 4.16. Evolution of GDP per capita among initially-poor,
initially-middle-income and initially-rich countries, 1940-2000.
Why did the very significant increases in life expectancy and health not cause
improvements in GDP per capita? The most natural answer to this question comes
from neoclassical growth theory (presented in the previous two chapters and in
Chapter 8 below). The first-order effect of increased life expectancy is to increase
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