1977, PhD in Economics, Massachusetts Institute of Technology. Macroeconomist; has worked on a wide set of issues, from the role of monetary policy, to the nature of speculative bubbles, to the nature of the labour market and the determinants of unemployment, to transition in former communist countries. Formerly, taught at Harvard University. Since 1982, with the Massachusetts Institute of Technology; currently on leave from MIT as Economic Counsellor and Director, Research Department, International Monetary Fund. Author of many books and articles, including two textbooks in macroeconomics, one at the graduate level with Stanley Fischer, one at the undergraduate level.