A number of books on economic psychology have appeared in the past few years. The most recent publications are by MacFadyen and Mac­ Fadyen (1986), Furnham and Lewis (1986), Lea et al. (1987) and Van Raaij et al. (1988). Why produce yet another book for this discipline? This question can be answered in various ways. In a sense, this book is the answer in itself. Its presentation of re­ search and theories is innovative in this field, at least to my knowledge. It attempts to structure the many theories emerging in the interdisci­ plinary science of economic psychology and to explain the background of the research. The second answer is pragmatic. In our introductory course of eco­ nomic psychology for economics students at Erasmus University Rot­ terdam we used several of the above mentioned books. Our experience with this material is that, when preparing our lectures, we had to ex­ plain many additional theories and experiments to our students. fur­ thermore, diagrams, figures and examples had to be culled from other sources or made by ourselves. It is not my intention to run down these publications since I think they provide an excellent treatment of a num­ ber of topics by specialists in economic psychology. The plan for the present book, however, emerged from our need to present an integrated introductory course for our students.