The Effect of Health on Economic Growth: Theory and Evidence

Macroeconomists acknowledge the contribution of human capital to economic growth, but their empirical studies define human capital solely in terms of schooling. In this paper, we extend production function models of economic growth to account for two additional variables that microeconomists have identified as fundamental components of human capital: work experience and health. Our main result is that good health has a positive, sizable, and statistically significant effect on aggregate output. We find little variation across countries in average work experience, thus differentials in work experience account for little variation in rates of economic growth. Finally, we find that the effects of average schooling on national output are consistent with microeconomic estimates of the effects of individual schooling on earnings, suggesting that education creates no discernible externalities.

Economic Growth and the Demographic Transition

For decades, economists and social thinkers have debated the influence of population change on economic growth. Three alternative positions define this debate: that population growth restricts, promotes, or is independent of economic growth. Proponents of each explanation can find evidence to support their cases. All of these explanations, however, focus on population size and growth. In recent years, however, the debate has under-emphasized a critical issue, the age structure of the population (that is, the way in which the population is distributed across different age groups), which can change dramatically as the population grows. Because people's economic behavior varies at different stages of life, changes in a country's age structure can have significant effects on its economic performance. Nations with a high proportion of children are likely to devote a high proportion of resources to their care, which tends to depress the pace of economic growth. By contrast, if most of a nation's population falls within the working ages, the added productivity of this group can produce a 'demographic dividend' of economic growth, assuming that policies to take advantage of this are in place. In fact, the combined effect of this large working-age population and health, family, labor, financial, and human capital policies can create virtuous cycles of wealth creation. And if a large proportion of a nation's population consists of the elderly, the effects can be similar to those of a very young population. A large share of resources is needed by a relatively less productive segment of the population, which likewise can inhibit economic growth. After tracing the history of theories of the effects of population growth, this report reviews evidence on the relevance of changes in age structure for economic growth. It also examines the relationship between population change and economic development in particular regions of the world: East Asia; Japan; OECD, North America and Western Europe; South-central and Southeast Asia; Latin America; Middle East and North Africa; Sub-Saharan Africa; and Eastern Europe and the former Soviet Union. Finally, it discusses the key policy variables that, combined with reduced fertility and increases in the working-age population, have contributed to economic growth in some areas of the developing world.

Technological Diffusion, Conditional Convergence, and Economic Growth

Technological diffusion implies a form of 'conditional convergence' as lagging countries catch up with technological leaders. We find strong evidence of technological diffusion but not full convergence; differences in total factor productivity (TFP) persist even in the long run due to differences in geography and institutions. TFP differentials explain a large part of cross-country income differences in our model; our estimates of the rate of return to capital, labor and schooling are completely consistent with micro-economic studies, implying the absence of externalities in aggregate production.

The Wealth of Nations: Fundamental Forces Versus Poverty Traps

We test the view the large differences in income levels we see across the world are due to differences in underlying characteristics, i.e. fundamental forces, against the alternative that there are poverty traps. Taking geographical variables as fundamental characteristics, we find that we can reject fundamental forces in favor of a poverty trap model with high and low level equilibria. The high level equilibrium state is found to be the same for all countries while income in the low level equilibrium, and the probability of being in the high level equilibrium, are greater in cool, coastal countries with high, year- round, rainfall.