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 microdata from the 1994–1998 International Adult Literacy Survey for nine countries, we examine the role of cognitive skills in explaining higher wage inequality in the United States. We find that while the greater dispersion of cognitive test scores in the United States plays a part in explaining higher U.S. wage inequality, higher labor market prices (i.e., higher returns to measured human capital and cognitive performance) and greater residual inequality still play important roles, and are, on average, quantitatively considerably more important than differences in the distribution of test scores in explaining higher U.S. wage inequality.

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.

The U.S. labor market has recently experienced two dramatic trends: a falling male-female pay gap and a rising level of labor-market inequality. After decades of near-constancy at about 60 percent, the ratio of women's to men's pay has risen steadily since the late 1970's. At the same time, there were substantial increases in overall wage inequality for both men and women (Lawrence F. Katz and Kevin M. Murphy, 1992; Blau and Kahn, 1993). Wage inequality rose both within and between education and experience groups, and this has been interpreted as reflecting primarily higher returns to both measured and unmeasured labor-market skills (Katz and Murphy, 1992; Chinhui Juhn et al., 1993). This paper addresses the connection between these two important developments. When analyzing gender differentials in pay, economists commonly focus on malefemale differences in skills and on differences in the treatment of equally qualified men and women (i.e., discrimination). Both of these may be considered gender-specific factors influencing the pay gap. Research on these gender-specific factors suggests that women tend to be less skilled than men, on average, and to be located in lower-paying industries and occupations. This in turn suggests that overall wage structure can also have an important effect on the gender pay gap. (Wage structure describes the array of prices set for various labor-market skills, measured and unmeasured, and the rents received for employment in particular sectors of the economy.) For example, since women on average have less experience than men, an increase in the return to experience (as in fact occurred over the 1970s and 1980s) would cause the gender pay gap to rise, even if women's relative level of experience and their gender-specific treatment by employers remained the same. Similarly, an increase in the returns to employment in male occupations and industries would widen the gender differential, all else equal. In earlier work, we found overall wage inequality to be very important in explaining international differences in the gender pay gap (Blau and Kahn, 1992, 1994). In particular, we addressed a paradox. On the one hand, U.S. women compare favorably to those in other countries in terms of their relative qualifications and occupational status. Further, the United States has had a longer and often stronger commitment to equal pay and equal employment policies than most other industrialized countries. Yet the gender pay gap in the United States is larger than in most of these countries. An important part of the explanation for this pattern is the high level of wage inequality (i.e., high returns to skill) in the United States, which puts an exceptionally large penalty on being below average in the wage distribution. Our results suggest that the U.S. gap would be similar to that in countries like Sweden or Australia (the countries with the smallest gaps) if the United States had their level of wage inequality. The implication of our earlier research on international differences in the gender gap is that in recent years American women have been swimming upstream in a labor market that was growing increasingly unfavorable to low-wage workers. In the face of this rising inequality, women's relative skills and treatment have to improve merely for the pay gap to remain constant; still larger gains are necessary for it to be reduced. * Blau: Institute of Labor and Industrial Relations, University of Illinois, Champaign, IL 61820, and NBER; Kahn: Institute of Labor and Industrial Relations, University of Illinois. We thank Claudia Goldin and participants at the NBER Labor Studies meeting and the University of Illinois and Cornell Labor Economics Workshops for helpful comments, and Jennifer Berdahl for excellent research assistance. Portions of this work were completed while the authors were visiting fellows at the Australian National University, Canberra.

This paper studies the considerably higher level of wage inequality in the United States than in nine other OECD countries. The authors find that the greater overall U.S. wage dispersion primarily reflects substantially more compression at the bottom of the wage distribution in the other countries. While differences in the distribution of measured characteristics help to explain some aspects of the international differences, higher U.S. prices (i.e., rewards to skills and rents) are an important factor. Labor market institutions, chiefly the relatively decentralized wage-setting mechanisms in the United States, provide the most persuasive explanation for these patterns.

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.

The Role of the Family in Immigrants' Labor-Market Activity: An Evaluation of Alternative Explanations: Comment by Francine D. Blau, Lawrence M. Kahn, Joan Y. Moriarty and Andre Portela Souza. Published in volume 93, issue 1, pages 429-447 of American Economic Review, March 2003