摘要：In this paper, we revisit the Mulligan and Rubinstein (2008: Selection, investment and women'srelative wages over time. The Quarterly Journal of Economics, 123(3):1061-1110) analysis aboutthe composition of the female workforce in the United States. Using a Heckman selection model,these authors found that the selection of women into the female workforce changed from nega-tive to positive over time. However, the authors assumed the exogeneity of covariates, which issometimes appropriate but not for a variable like education. We revisit the issue of the Mulliganand Rubinstein (2008) paper by developing and applying a Heckman selection model which alsocontrols for the potential endogeneity of education. Applying this estimator to U.S. Census andAmerican Community Survey data, we find that selection has become more positive over time(like in Mulligan and Rubinstein), but that selection has never been negative. We rather find aninteresting puzzle concerning the correlation pattern of the unobservables in our model whichrequires further investigation
关键词：Sample selection model; endogenous covariates; gender wage gap; composition;of the female workforce; female labor force participation
