Mark Gersovitz is Professor of economics at The Johns Hopkins University. He specializes in applying microeconomics to the study of the economies of poor countries. Current research includes the economics of health especially infectious diseases and HIV in Africa. His past and ongoing research interests include international capital mobility, international trade, public finance, agriculture, domestic savings. He has traveled widely for professional reasons, primarily in Africa but also in Asia and the Middle East/North Africa. He has been a consultant to the World Bank, the IMF, the UNDP among other organizations and was Editor of The World Bank Research Observer and The World Bank Economic Review, 1992-94.