Sergio Díaz-Briquets is with Casals & Associates, a consulting firm in Washington, D.C. He was research director of the Commission for the Study of International Migration and Cooperative Economic Development, created by Congress. Earlier he held appointments with Duquesne University in Pittsburgh and with the Population Reference Bureau in Washington, D.C., and was a program officer with the International Development Research Centre (IDRC) in Ottawa, Canada. Diaz-Briquets has been a consultant to the U.S. Agency for International Development, the World Bank, and other international development agencies. Holder of a Ph.D. from the University of Pennsylvania, Diaz-Briquets is the author of several books on a variety of development-related topics, including The Health Revolution in Cuba (1983), and coauthor of Social Change and Internal Migration (1977). Most recently he edited Cuban Internationalism in Sub-Saharan Africa (1989). Sidney Weintraub is Dean Rusk Professor and director of the Program for U.S.-Mexico Policy Studies at the Lyndon B. Johnson School of Public Affairs at the University of Texas at Austin. He is also a Distinguished Visiting Scholar at the Center for Strategic and International Studies (CSIS). As a career diplomat (1949-1975), he was an assistant administrator of the Agency for International Development, Deputy Assistant Secretary of State for international finance and development, chief of the AID mission in Chile under the Alliance for Progress, and chief of commercial policy in the State Department. Dr. Weintraub also has authored numerous books and monographs focusing on Mexico-United States relations, including Mexican Trade Policy and the North American Community (1988), Industrial Strategy and Planning in Mexico and the United States (Westview, 1986), Free Trade Between Mexico and the United States? (1984), and A Marriage of Convenience: Relations Between Mexico and the United States (1990). He is coeditor with Luis F. Rubio and Alan D. Jones of U.S.-Mexican Industrial Integration (Westview, 1991).