Economics has paid little attention to the psychology of economic behaviour, leading to somewhat simplistic assumptions about human nature. The psychological aspects have typically been reduced to standard utility theory, based on a narrow conception of rationality and self-interest maximization. The contributions in this volume, some focused on analytical models and methodology, others on laboratory and field experiments, challenge these assumptions, and provide novel and complex understandings of human motivation and economic decision-making. With a pioneering introduction by the book's two editors, this volume brings together exciting contributions to a field that is rapidly growing in influence and reach.

RONALD BENABOU Woodrow Wilson School, Princeton University, USA
FREIDEL BOLLE Europa-Universität Viadrina, Frankfurt (Oder), Germany
JUAN-CAMILO CARDENAS Universidad de los Andes, Bogota, Colombia
OTTARINO CHILLEMI Università di Padova, Italy
FLORIAN ENGLMAIER Universität München, Germany
ERNST FEHR Institut für Empirische Wirtschaftsforschung, Universität Zürich, Switzerland
ALEXANDER KRITIKOS Europa-Universität Viadrina, Frankfurt (Oder), Germany
JOCHEN JUNGEILGES Universität Bielefeld, Germany
ODED STARK ZEF, Universität Bonn, Germany
THEIS THEISEN School of Management, Agder University College, Kristiansand, Norway
JEAN TIROLE Institut d'Economie Industrielle, Université de Toulouse, France
JEAN-ROBERT TYRAN Institute of Economics, University of Copenhagen, Denmark
ALEXANDER VASIN Moscow State University, Russian Federation
YONG WANG City University of Hong Kong, China
YOU QUIANG WANG School of Public Policy and Management, Tsinghua University, Beijing, China

Introduction; B.Agarwal & A.Vercelli PART 1: ANALYTICAL MODELS AND METHODOLOGICAL ISSUES Self-Confidence and Personal Motivation; R.Benabou & J.Tirole Rationality, Learning and Complexity; A.Vercelli Altruism: Evolution and a Repercussion; O.Stark, Y.Q.Wang & Y.Wang Human Reproduction and Utility Functions: An Evolutionary Approach; A.Vasin Moral Hazard, Contracts and Social Preferences: A Survey; F.Englmaier Mutual Concern, Workplace Relationships and Pay Scales; O.Chillemi PART 2: LABORATORY AND FIELD EXPERIMENTS Expectations and the Effects of Money Illusion; E.Fehr & J-R.Tyran Utility-Based Altruism: Evidence from Experiments; F.Bolle & A.Kritikos Equity Judgements Elicited through Experiments: An Econometric Examination; J.Jungeilges & T.Theisen Groups, Commons and Regulations: Experiments with Villagers and Students in Columbia; J-C.Cardenas