individual been honored at the time of his death with ceremonies from the national associations of all three of these disciplines. The purpose of this book is to introduce to a broad constituency of social scientists and their students some of the basic ideas in the study of the labor force that Cliff and his colleagues had grappled with. At the time of Cliff's death, he was perhaps better known for his methodological contributions to sociology and demography than he was for his substantive contributions to the study of social stratification and the labor force. Our goal is to highlight Cliff's substantive contributions to sociology and demography by telling the cumulative story of his research and adding updated analysis that advances the story beyond the early 1980s to the mid-1990s.