Economic growth and economic development 217

Introduction to Modern Economic Growth
estimates and argues that differences in health capital emerge as an important factor
in accounting for cross-country differences in income levels.
The idea that part of the low productivity of less-developed nations is due to
the unhealthy state of their workforces has obvious appeal. The micro evidence and
the work by David Weil shows that it has some empirical validity as well. But does
it imply that geographic factors are an important fundamental cause of economic
growth? Not necessarily. As already mentioned above, the burden of disease is
endogenous. Today’s unhealthy countries are unhealthy precisely because they are
poor and are unable to invest in health care, clean water and other health-improving
technologies. After all, much of Europe was very unhealthy and suffering from low
life expectancy only 200 years ago. This changed with economic growth. In this
sense, even if “health capital” is a useful concept and does contribute to accounting
for cross-country income differences, it may itself be a proximate cause, affected by
other factors, such as institutions or culture.

4.6

4.4

4.2

4

3.8

3.6

3.4

3.2

3
1930

1940

1950

Initially Rich

1960

1970

Initially Middle Income

1980

1990

2000

Initially Poor

Figure 4.15. Evolution of life expectancy at birth among initiallypoor, initially-middle-income and initially-rich countries, 1940-2000.
A recent paper by Acemoglu and Johnson (2006) directly investigates the impact of changes in disease burdens on economic development. They exploit the
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