A quantitative theory of the gender gap in wages

This paper measures how much of the gender wage gap over the life cycle is due to the fact that working hours are lower for women than for men. We build a quantitative theory of fertility, labor supply, and human capital accumulation decisions to measure gender differences in human capital investments over the life cycle. We assume that there are no gender differences in the human capital technology and calibrate this technology using wage-age profiles of men. The calibration of females assumes that children involves a forced reduction in hours of work that falls on females rather than on males and that there is an exogenous gender gap in hours of work. We find that our theory accounts for all of the increase in the gender wage gap over the life cycle in the NLSY79 data. The impact of children on the labor supply of females accounts for 56% and 45% of the increase in the gender wage gap over the life cycle among non-college and college females, while the rest is due to the exogenous gender differences in hours of work.