1. International Economist, U.S. Department of the Treasury, Office of International Trade, 1500 Pennsylvania Avenue, NW, Washington, DC 20220.
2. Professor of Economics, School of Social Sciences, University of Sussex, Falmer, BRIGHTON, BN1 9QN, United Kingdom, Centre for Economic Policy Research, 90-98 Goswell Road, London, EC1V 7DB, England; and Centre for Economic Performance, London School of Economics, Houghton Street, London WC2A 2AE, England.