We assemble a new matched employer-employee data set covering essentially all industries and occupations across all regions of the U.S. We use this data set to re-examine the question of the relative contributions to the overall sex gap in wages of sex segregation vs. wage differences by sex within occupation, industry, establishment, and occupation-establishment cells. This new data set is especially useful because earlier research on this topic relied on data sets that covered only a narrow range of industries, occupations, or regions. Our results indicate that a sizable fraction of the sex gap in wages is accounted for by the segregation of women into lower-paying occupations, industries, establishments, and occupations within establishments. Nonetheless, a substantial part of the sex gap in wages remains attributable to the individual's sex. This latter finding contrasts sharply with the conclusions of previous research (especially Further research into the sources of withinestablishment within-occupation sex wage differences is therefore much more important than previously thought.

The Interaction of Public Retirement Income Programs in the United States by Elizabeth T. Powers and David Neumark. Published in volume 93, issue 2, pages 261-265 of American Economic Review, May 2003