This is the first systematic international comparative study of the transformation of couples' careers in modern societies. The countries included are Germany, the Netherlands, the Flemish part of Belgium, Italy, Spain, Great Britain, the United States, Sweden, Denmark, Poland, Hungary, and China. Using longitudinal data, this book explores what has and what has not changed for couples in various countries due to women's greater involvement in paid employment. It provides evidence that despite substantial improvement in women's educational attainment and career opportunities in all the countries studied, dimensions of role specialization in dual-earner couples have not undergone transformation to the same extent. Gender role change within the family has generally been asymmetric, so that housework and childcare primarily remain 'women's work'. There are, however, also significant institutional differences among modern societies which determine a country's timing, speed, and pattern of change from the traditional male breadwinner to the dual-earner family model. In particular, the impact of males' resources on their female partners' employment careers is dependent on the welfare state regime. In conservative and Mediterranean welfare state regimes, women's paid employment is negatively correlated with the occupational position of their husbands. In liberal welfare state regimes, no impact of husbands' resources on their wives' labour force participation could be detected. In the social democratic welfare state regime and generally in (former) socialist countries, husbands' resources have a positive effect on their wives' employment so that occupational resources cumulate in dual-earner families.