Assistant Professor, Professor of Economics, Growth Center, Yale University, 1961-1965,
1969-1983. Economics Staff Committee Nine, Alliance for Progress, Organization American States, 1962-1963. Association Professor of Economics, University Minnesota, 1965-1969.
Consultant, Interamer. Committee Alliance Progress, Pan American Union, 1965-1966. Massachusetts Institute of Technology, Cambridge, Mass., USA/ODEPLAN, Santiago, Chile, Project Andean Common Market, 1967-1968.
Member, Commission International Development (‘Pearson Commission’), 1968-1969. Visiting Professor of Economics, Pontificia University Catolica Rio de Janeiro, 1971. Visiting Scholar, Nuffield College Oxford, 1975-1976.
Professor of Economics, Columbia University, New York, 1983-1985. Editorial Board, World Development (United Kingdom). Co-editor, Journal of Development Economics, 1976-1985.
Consultant, Commission United States-Latin American Relations (‘Linowitz Commission’), 1975. Chair
man, Joint Committee Latin American Studies, United States Social Science Research Council, United Kingdom or United States of America, 1976-1979. Member, Council Foreign Relations, New York, since 1977.
Member, American Economic Association Policy Advisory Board, Economics Institute, Institution, Boulder, Colorado, 1977-1980. Member, Academic Panel Consultative Group International Economics Monetary Affairs, Rockefeller Foundation, 1978. Member, United States Bipartisan Commission Central American, since 1979.