All industrialized countries experienced a transition from high birth rates and stagnant standards of living to low birth rates and sustained growth in per capita income. What contributed to these transformations? Did economic and demographic changes transpire through common or distinct channels? We construct a general equilibrium model with endogenous fertility in order to quantitatively investigate the English case. We find that mortality decline significantly influences birth rates. Increased productivity has a negligible effect on birth rates but accounts for nearly all of the increase in per capita output, industrialization, urbanization, and the decline of land share in total income. The quantitative assessment of these two channels (young-age mortality and productivity) conducted in this paper sheds light on the relative importance of several theoretical mechanisms developed in this field.

A negative relationship between income and fertility has persisted for so long that its existence is often taken for granted. One economic theory builds on this relationship and argues that rising inequality leads to greater differential fertility between rich and poor. We show that the relationship between income and fertility has flattened between 1980 and 2010 in the US, a time of increasing inequality, as high income families increased their fertility. These facts challenge the standard theory. We propose that marketization of parental time costs can explain the changing relationship between income and fertility. We show this result both theoretically and quantitatively, after disciplining the model on US data. We explore implications of changing differential fertility for aggregate human capital. Additionally, policies, such as the minimum wage, that affect the cost of marketization, have a negative effect on the fertility and labor supply of high income women. We end by discussing the insights of this theory to the economics of marital sorting.

Economic growth, Total factor productivity, Adult mortality, Longevity, Knowledge transmission, Ideas, Human capital, O40, O31, O33, J10, N10,

Mulligan and Rubinstein (2008) (MR) argued that changing selection of working females on unobservable characteristics, from negative in the 1970s to positive in the 1990s, accounted for nearly the entire closing of the gender wage gap. We argue that their female wage equation estimates are inconsistent. Correcting this error substantially weakens the role of the rising selection bias (39 % versus 78 %) and strengthens the contribution of declining discrimination (42 % versus 7 %). Our findings resonate better with related literature. We also explain why our finding of positive selection in the 1970s provides additional support for MR's main hypothesis that an exogenous rise in the market value of unobservable characteristics contributed to the closing of the gender gap.