This research would not have been possible without the financial support of the W.E. Upjohn Institute for Employment Research. I also appreciate the assistance and comments of the Upjohn Institute staff economists. Allan Hunt, Kevin Hollenbeck, and Stephen Woodbury were particularly helpful. In addition, I would like to thank the following people who were instrumental in the completion of this project: Jack McNeil and Vic Valdisera of the U.S. Census Bureau, Bob McIntire of the U.S. Bureau of Labor Statistics, David Autor, Christopher Bollinger, Barry Hirsch, Doug Kruse, David Macpherson, Robert Margo, Walter Oi, and my colleagues Robert E. Moore and M. Melinda Pitts. The research assistance and contributions of Ludmila Rovba are without measure. Generosa Kagaruki also provided valuable research help. Lastly, I would like to dedicate this book to my parents, Burt and Nonnie Hotchkiss.