We use data on sisters to jointly address heterogeneity bias and endogeneity bias in estimates of wage equations for women. This analysis yields evidence of biases in OLS estimates of wage equations for white and black women, some of which are detected only when these two sources of bias are...

The human capital explanation of sex differences in wages is that women intend to work in the labor market more intermittently than men, and therefore invest less. This lower investment leads to lower wages and wage growth. The alternative "feedback" hypothesis consistent with the same facts is...