The present dissertation consists of four studies. The first study serves as a descriptive background to the following three self-contained but interrelated empirical studies. The joint theme is horizontal labour market sex segregation.

Study I describes changes in workplace, organizational and occupational sex segregation in Sweden between 1990 and 2003, a period under study in the following studies. The study shows that there is a modest decrease in workplace sex segregation, a somewhat more marked decrease in occupational sex segregation, and a modest increase in organizational sex segregation between 1990 and 2003.

Study II examines mechanisms behind sex segregation at Swedish workplaces by focusing on the process through which workplaces renew their workforce, by using a sample of 1,460 workplaces that recruited 75,261 employees between 1991 and 1995. The results indicate that the most important factor in reproducing segregation at workplaces is sex segregation in the occupations from which workplaces recruit their personnel.

Study III analyses sources of the sex wage gap in Sweden and Japan by focusing on the significance of human capital, workplace sex segregation, and family situation, using recent and nationwide individual-level data. The results suggest that human capital factors and women’s heavier family responsibilities account for more of the sex wage gap in Japan than in Sweden, whereas workplace sex segregation accounts for more of the sex wage gap in Sweden compared to Japan.

Study IV examines employees’ patterns of mobility between occupations of different sex proportions in 2002 and 2003, based on a large-scale data set with a panel design. The results indicate that employees’ occupational shifts strengthen sex segregation across occupations and that, when we compare women and men who in 2002 were in occupations with a given sex proportion, employees shift to more sex-typical occupations relative to employees of the opposite sex.