This volume was originally prepared for the National Council on Employment Policy. It is based upon research sponsored by the U.S. Department of Labor, the Sloan Foundation, and the Ford Foundation.

The argument draws heavily upon interviews with migrants and with various people who work with migrants and migrant communities in an official or professional capacity. Without their cooperation, the book would not have been possible.

I am also indebted to a number of students and colleagues whose own research I have drawn upon and who have been helpful in the development of these ideas. The list of people who contributed in this way is too long to include here. Particularly important were my colleagues on the Ford Foundation dualism project, Suzanne Berger, Lisa Peattie, and Martin Rein. I am also grateful to Myron Weiner and the Migration and Development Study Group, which he organized, for creating an institutional framework supportive of work of this kind and to the Center for International Studies at MIT in which both the dualism project and the Study Group have been housed. I am especially indebted as well to Duncan Foley, Charles Myers, Charles Sabel, and Peter Temin, all of whom offered extensive critical comment and advice. This would no doubt be a better book if I had managed to respond more fully to their criticism and accepted more of their suggestions. Finally, I am grateful for the help and support of my wife, Nancy, and my children, Adam and Ana. In a certain sense, the book is really for them.