George Tsebelis is the Anatol Rapoport Collegiate Professor of Political Science at the University of Michigan where he works on political institutions. He is a member of the American Academy of Arts and Sciences and has received honorary degrees from the Universities of Athens, Crete and Milan. He is the author (among other books) of Nested Games: Rational Choice in Comparative Politics (1991) and Veto Players: How Political Institutions Work (2002).