Human Capital, Fertility, and Economic Growth
Our model of growth departs from both the Malthusian and neoclassical approaches by including investments in human capital. We assume, crucially, that rates of return on human capital investments rise, rather than, decline, as the stock of human capital increases, until the stock becomes large. This arises because the education sector uses human capital note intensively than either the capital producing sector of the goods producing sector. This produces multiple steady scares: an undeveloped steady stare with little human capital, low rates of return on human capital investments and high fertility, and a developed steady stats with higher rates of return a large, and, perhaps, growing stock of human capital and low fertility. Multiple steady states mean that history and luck are critical determinants of a country's growth experience.
Journal of Political Economy, vol. 98, no. 5, pages S12-37 (October 1990).
Human Capital, Fertility, and Economic Growth, Gary S. Becker, Kevin M. Murphy, Robert Tamura. in Human Capital: A Theoretical and Empirical Analysis with Special Reference to Education, Third Edition, Becker. 1994