In this paper we use a new data set describing households with and without twin children in China to quantify the trade-off between the quality and quantity of children using the incidence of twins that for the first time takes into account effects associated with the lower birthweight and...

We use a model of human capital investment and activity choice to explain facts describing gender differentials in the levels and returns to human capital investments. These include the higher return to and level of schooling, the small effect of healthiness on wages, and the large effect of...