Data from the United States Census of Population indicate that there has been a dramatic increase in the labor force participation of married women over the twentieth century. This book, first published in 1998, takes issue with this well-known stylized fact. Whereas the labor force literature comments extensively on men's transition from home production to market work, the effect on women's employment has gone more or less unnoticed. The objective of this book is to uncover the work usually omitted from descriptions of wage work and housework - that is, work done in the household for market use - and to examine the various implications of this omission for analysing married women's participation in GNP-producing work over the course of the past century.