Marriage, Motherhood, and Wages
探讨从婚姻、母亲身份与工资的横截面关系中推断因果效应时存在的问题，发现异质性导致有偏估计，一阶差分显示无直接效应，而工具变量估计表明儿童对工资的负向影响被低估。
We explore several problems in drawing causal inferences from cross-sectional relationships between marriage, motherhood, and wages. We find that heterogeneity leads to biased estimates of the effects of marriage and motherhood on wages (i.e., effects net of experience and tenure); first-difference estimates reveal no direct effect of marriage or motherhood on women's wages. We also find statistical evidence that experience and tenure nay be endogenous variables in wage equations; IV estimates suggest that both OLS cross-sectional and first-difference estimates understate the direct (negative) effect of children on wages.