This book provides the first comparative study of the long-term development of women's part-time work in Europe and the United States from 1950 onwards. The authors analyze a wealth of longitudinal and cross-sectional data on the work force, generating a powerful critique of the dominant theories that part-time work equalizes women's position vis à vis full-time workers or leaves women in part-time jobs wholly marginalized. Instead, the study asserts, women's increasing part-time employment in modern societies must be examined in the context of the sexual division of labor within the family.