Paul Krugman joined The New York Times in 1999 as a columnist on the Op-Ed Page and continues as professor of Economics and International Affairs at Princeton University.  His professional reputation rests largely on work in international trade and finance; he is one of the founders of the “new trade theory,” a major rethinking of the theory of international trade.  Mr. Krugman won the Nobel Prize for Economics in 1998 for his analysis of trade patterns and location of economic activity.