The "human capital earnings function," in which earnings are expressed as a quadratic in potential experience, is probably the most widely accepted empirical specification in economics. In spite of its widespread acceptance, the human capital earnings function provides a very poor approximation...

The authors' analysis of growth assumes endogenous fertility and a rising rate of return on human capital as the stock of human capital increases. When human capital is abundant, rates of return on human capital investments are high relative to rates of return on children, whereas, when human...

The authors develop a theory of rational addiction in which rationality means a consistent plan to maximize utility over time. Strong addiction to a good requires a big effect of past consumption of the good on current consumption. Such powerful complementarities cause some steady states to be...