Using Panel Study of Income Dynamics (PSID) microdata over the 1980–2010 period, we provide new empirical evidence on the extent of and trends in the gender wage gap, which declined considerably during this time. By 2010, conventional human capital variables taken together explained little of the gender wage gap, while gender differences in occupation and industry continued to be important. Moreover, the gender pay gap declined much more slowly at the top of the wage distribution than at the middle or bottom and by 2010 was noticeably higher at the top. We then survey the literature to identify what has been learned about the explanations for the gap. We conclude that many of the traditional explanations continue to have salience. Although human-capital factors are now relatively unimportant in the aggregate, women's work force interruptions and shorter hours remain significant in high-skilled occupations, possibly due to compensating differentials. Gender differences in occupations and industries, as well as differences in gender roles and the gender division of labor remain important, and research based on experimental evidence strongly suggests that discrimination cannot be discounted. Psychological attributes or noncognitive skills comprise one of the newer explanations for gender differences in outcomes. Our effort to assess the quantitative evidence on the importance of these factors suggests that they account for a small to moderate portion of the gender pay gap, considerably smaller than, say, occupation and industry effects, though they appear to modestly contribute to these differences.

Using Michigan Panel Study of Income Dynamics data, we study selection bias and the gender wage gap. Employing several methods, we find large declines in the total and unexplained gender gaps in wage offers between 1981 and 2015. Under our preferred selection correction method, the median total and unexplained gaps fell by 0.378 and 0.204 log points, respectively. These are larger declines than if we had not corrected for selection and simply measured convergence in observed wage gaps. However, substantial selectivity-corrected median gender wage gaps remain in 2015: 0.242 log points (total gap) and 0.206 log points (unexplained gap).

In 1990, the US had the sixth highest female labor participation rate among 22 OECD countries. By 2010 its rank had fallen to seventeenth. We find that the expansion of “family-friendly” policies, including parental leave and part-time work entitlements in other OECD countries, explains 29 percent of the decrease in US women's labor force participation relative to these other countries. However, these policies also appear to encourage part-time work and employment in lower level positions: US women are more likely than women in other countries to have full time jobs and to work as managers or professionals.

Using 1980–2000 Census data to study the impact of source country characteristics on married adult immigrants' labor supply assimilation profiles, we find that immigrant women from countries with high female labor supply persistently work more than those from low-female-supply countries. While both groups of women work less than comparable natives on arrival, women from high-female-participation countries eventually close the gap with natives entirely, and women from low-female-labor supply countries eliminate most of it. Men's labor supply is unaffected by source country female participation, suggesting that the findings on women reflect notions of gender roles.