Endogenous fertility, mortality, and economic growth

"The 19th century economist, Thomas Robert Malthus, hypothesized that the long-run supply of labor is completely elastic at a fixed wage-income level because population growth tends to outstrip real output growth. Dynamic equilibrium with constant income and population is achieved through equilibrating adjustments in "positive checks" (mortality, starvation) and "preventive checks" (marriage, fertility). Developing economies since the Industrial Revolution, and more recently especially Asian economies, have experienced steady income growth accompanied by sharply falling fertility and mortality rates. We develop a dynamic model of endogenous fertility, longevity, and human capital formation within a Malthusian framework that allows for diminishing returns to labor but also for the role of human capital as an engine of growth. Our model accounts for economic stagnation with high fertility and mortality and constant population and income, as predicted by Malthus, but also for takeoffs to a growth regime and a demographic transition toward low fertility and mortality rates, and a persistent growth in per-capita income"--National Bureau of Economic Research web site.