Visiting Fellow (1996–97), spent over 20 years at the World Bank and its private investment affiliate, the International Finance Corporation. He was a professor of economics at Colombia University (1964-68), Stanford University (1968-72), and the University of North Carolina at Chapel Hill (1972-75) before joining the World Bank in 1975. He is the author of Improving Trade Policy Reviews in the World Trade Organization (1998) in addition to numerous publications on international trade.