ERNST FEHR is Director of the Institute for Empirical Research in Economics at the University of Zurich, Switzerland. Professor Fehr is also a Fellow at the Collegium Helveticum, Affiliated Faculty Member of the Department of Economics at MIT, Director of the Ludwig Boltzman Institute for the Analysis of Economic Growth, Vice President of the European Economic Association, and a Fellow with the Centre for Economic Policy Research, the CESifo Group, and the Institute for the Study of Labor. He is the author of nearly 100 articles and three books, including Economic Theory of Self-Management and Profit-Sharing (1988), Foundations of Human Sociality: Economic Experiments and Ethnographic Evidence from Fifteen Small Scale Societies (2004), and most recently, Moral Sentiments and Material Interests (2005, with Robert Boyd, Samual Bowles and Herbert Gintis).