Experiments On Decisions Under Risk The Expected Utility Hypothesis

In this valuable book, Paul Schoemaker summarizes recent experimental and field research that he and others have undertaken regarding the descrip tive validity of expected utility theory as a model of choice under uncer tainty. His principal message is that this paradigm is too narrow in its con ception and misses some of the important elements of a descriptive model of individual choice. In particular, Schoemaker calls attention to the impor tance of individual differences, task effects, and context effects as they influence behavior. The expected utility hypothesis has come under scrutiny in recent years from a number of different quarters. This book brings together these many studies and relates them to the large body of literature on individual de cision making under risk. Although this paradigm may be appropriate for describing behavior under many conditions of uncertainty, Schoemaker presents convincing evidence that it does not do well with respect to protec tion against low-probability events. For example, he shows that the insur ance purchase decision is influenced by the way information is presented to the client, as well as by the statistical knowledge of the respondents.

Uncertain Decisions: Bridging Theory and Experiments presents advanced directions of thinking on decision theory - in particular the more recent contributions on non-expected utility theory, fuzzy decision theory and case-based theory. This work also provides theoretical insights on measures of risk aversion and on new problems for general equilibrium analysis. It analyzes how the thinking that underlies the theories described above spills over into real decisions, and how the thinking that underlies these real decisions can explain the discrepancies between theoretical approaches and actual behavior. This work elaborates on how the most recent laboratory experiments have become an important source both for evaluating the leading theory of choice and decision, and for contributing to the formation of new models regarding the subject.

Introduction to Statistical Decision Theory: Utility Theory and Causal Analysis provides the theoretical background to approach decision theory from a statistical perspective. It covers both traditional approaches, in terms of value theory and expected utility theory, and recent developments, in terms of causal inference. The book is specifically designed to appeal to students and researchers that intend to acquire a knowledge of statistical science based on decision theory. Features Covers approaches for making decisions under certainty, risk, and uncertainty Illustrates expected utility theory and its extensions Describes approaches to elicit the utility function Reviews classical and Bayesian approaches to statistical inference based on decision theory Discusses the role of causal analysis in statistical decision theory

Models and Experiments in Risk and Rationality presents original contributions to the areas of individual choice, experimental economics, operations and analysis, multiple criteria decision making, market uncertainty, game theory and social choice. The papers, which were presented at the FUR VI conference, are arranged to appear in order of increasing complexity of the decision environment or social context in which they situate themselves. The first section `Psychological Aspects of Risk-Bearing', considers choice at the purely individual level and for the most part, free of any specific economic or social context. The second section examines individual choice within the classical expected utility approach while the third section works from a perspective that includes non-expected utility preferences over lotteries. Section four, `Multiple Criteria Decision-Making Under Uncertainty', considers the more specialized but crucial context of uncertain choice involving tradeoffs between competing criteria -- a field which is becoming of increasing importance in applied decision analysis. The final two sections examine uncertain choice in social or group contexts.

Utility theory or, value theory in general, is certainly the cornerstone of decision theory, game theory, microecon~mics, and all social and political theories which deal with public decisions. Recently the American School of utility, founded by von N eumann Morgenstern, encountered a far-going criticism by the French School of utility represented by its founder Allais. The whole basis of the theory of decisions involving risk has been shaken and put into question. Consequently, basic research in the fundamentals of utility and value theory evolved into a crisis. Like any crisis in basic research, and this one was not an exception, it was very fruitful. One may simply say: Allais versus von Neumann-Morgenstern, or the French School of utility versus the American School, became one of the battlefields of scientific development which proved to be a most creative source of new advances and new developments in all those sciences which are based on evaluation of utilities.

As desired, the infonnation demand correspondence is single valued at equilibrium prices. Hence no planner is needed to assign infonnation allocations to individuals. Proposition 4. For any given infonnation price system p E . P (F *), almost every a E A demands a unique combined infonnation structure (although traders may be indifferent among partial infonnation sales from different information allocations, etc. ). In particular, the aggregate excess demand correspondence for net combined infonnation trades is a continuous function. Proof Uniqueness fails only if an agent can obtain the same expected utility from two or more net combined infonnation allocations. If this happens, appropriate slight perturbations of personal probability vectors destroy the equality unless the utility functions and wealth allocations were independent across states. Yet, when utilities and wealths don't depend on states in S, no infonnation to distinguish the states is desired, so that the demand for such infonnation structures must equal zero. To show the second claim, recall that if the correspondence is single valued for almost every agent, then its integral is also single valued. Finally, note that an upper hemicontinuous (by Proposition 2) correspondence which is single valued everywhere is, in fact, a continuous function. [] REFERENCES Allen, Beth (1986a). "The Demand for (Differentiated) Infonnation"; Review of Economic Studies. 53. (311-323). Allen, Beth (1986b). "General Equilibrium with Infonnation Sales"; Theory and Decision. 21. (1-33). Allen, Beth (1990). "Infonnation as an Economic Commodity"; American Economic Review. 80. (268-273).

In this volume we present some of the papers delivered at FUR-IV - the Fourth International Conference on Founda tions and Applications of Utility, Risk and Decision Theory in Budapest, June 1988. The FUR Conferences have provided an appreciated forum every two years since 1982 within which scientists can report recent issues and prospective applications of decision theory, and exchange ideas about controversial questions of this field. Focal points of the presented papers are: expected utility versus alterna tive utility models, concepts of risk and uncertainty, developments of game theory, and investigations of real decision making behaviour under uncertainty and/or in risky situations. We hope that this sample of papers will appeal to a wide spectrum of readers who are interested in and fami liar with this interesting and exciting issues of decision theory. A wide range of theoretical and practical questions is considered in papers included in this volume, and many of them closely related to economics. In fact, there were two Nobel-Laureates in economics among the participants: I. Herbert A. Simon (1978) and Maurice Allais (1988), who won the prize just after the conference. His paper deals with problems of cardinal utility. After a concise overview of the history and theory of cardinal utility he gives an estimate of the invariant cardinal utility function for its whole domain of variation (i. e.