Jon Elster (/ˈɛlstər/; born 22 February 1940, Oslo) is a Norwegian philosopher and political theorist who holds the Robert K. Merton professorship of Social Science at Columbia University. He received his PhD in social science from the École Normale Superieure in 1972. He has previously taught at the University of Paris, the University of Oslo, and the University of Chicago, where he became professor of political science in 1984. Since 1995, he has held the Robert K. Merton professorship of Social Science at Columbia University, as well as being professor of social science at the Collège de France since 2005.