Recent Developments In The Foundations Of Utility And Risk Theory

The Second International Conference on Foundations of Utility and Risk Theory was held in Venice, June 1984. This volume presents some of the papers delivered at FUR-84. (The First International Conference, FUR-82, was held in Oslo and some of the papers presented on that occasion were published by Reidel in the volume Foundations of Utility and Risk Theory with Applications, edited by Bernt P. Stigum and Fred Wenst~p). The theory of choice under uncertainty involves a vast range of controversial issues in many fields like economics, philosophy, psychology, mathematics and statistics. The idea of discussing these problems in international conferences has been successful: two conferences have been held and others will follow. The climate of the debate has changed in the meantime, partly as a result of these conferences. It is no more only a question of attacking or defending the neo-Bernoullian assumptions, but also of proposing wider generalizations and including new elements in the analysis of the decision process. For instance Amartya Sen - comparing the two current notions of rationality, internal consistency and self-interest pursuit introduces the concept of reasoning and considers the irrationality which may result from the failure of a positive correspondence between reasoning and choice or from a limited capacity of reasoning. Rationality is also considered with respect to the controversial axiom of strong independence. John C. Harsanyi introduces the concept of practical certainty, i. e.

In this volume we present some o~ the papers that were delivered at FUR-82 - the First International Con~erence on Foundations o~ Utility and Risk Theory in Oslo, June 1982. The purpose o~ the con~erence was to provide a ~orum within which scientists could report on interesting applications o~ modern decision theory and exchange ideas about controversial issues in the ~oundations o~ the theory o~ choice under un certainty. With that purpose in mind we have selected a mixture of applied and theoretical papers that we hope will appeal to a wide spectrum o~ readers ~rom graduate students in social science departments and business schools to people involved in making hardheaded decisions in business and government. In an introductory article Ole Hagen gives an overview o~ various paradoxes in utility and risk theory and discusses these in the light o~ scientific methodology. He concludes the article by calling ~or joint efforts to provide decision makers with warkable theories. Kenneth Arrow takes up the same issue on a broad basis in his paper where he discusses the implications o~ behavior under uncertainty for policy. In the theoretical papers the reader will ~ind attempts at de~initive Statements of the meaning o~ old concepts and suggestions for the adoption o~ new concepts. For instance, Maurice Allais discusses four di~ferent interpretations o~ the axioms o~ probability and explains the need ~or an empirical characterization o~ the concept of chance.

1. PROGRESS IN UTILITY AND RISK THEORY At the First International Congress of Utility and Risk Theory in Oslo 1982 (FUR-82) it appeared to be a widespread feeling among the participants that the conference signalled something like a paradigm shift in the field. This does not necessarily mean that old truths were discarded and replaced by new ones, but rather that new theories and new empirical evidence were brought forth, compelling old theories to be critically analyzed from new angels. Some of the papers presented at FUR-82 have been published by Reidel in 1983 in a volume edited by Stigum and Wenst0p. The present volume contains com mentaries on a number of the papers presented at the conference together with broader outlines of current views on the theory. The observation that utility and risk theory now appears to be in a state of rapid change has prompted us to choose the title PROGRESS IN UTILITY AND RISK THEORY for the book, in the belief that science always moves from poorer to more advanced paradigms or from weaker to more forceful theories. In other words, change is usually progress, even though intermediate stages in a para digm shift may be bewildering, to say the least.

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.

Each volume in this series includes a collection of authoritative essays from the New Palgrave: A Dictionary of Economics, selected by the Editors to illustrate the range and diversity of economic thought on a particular topic.

A through guide covering Modern Portfolio Theory as well as the recent developments surrounding it Modern portfolio theory (MPT), which originated with Harry Markowitz's seminal paper "Portfolio Selection" in 1952, has stood the test of time and continues to be the intellectual foundation for real-world portfolio management. This book presents a comprehensive picture of MPT in a manner that can be effectively used by financial practitioners and understood by students. Modern Portfolio Theory provides a summary of the important findings from all of the financial research done since MPT was created and presents all the MPT formulas and models using one consistent set of mathematical symbols. Opening with an informative introduction to the concepts of probability and utility theory, it quickly moves on to discuss Markowitz's seminal work on the topic with a thorough explanation of the underlying mathematics. Analyzes portfolios of all sizes and types, shows how the advanced findings and formulas are derived, and offers a concise and comprehensive review of MPT literature Addresses logical extensions to Markowitz's work, including the Capital Asset Pricing Model, Arbitrage Pricing Theory, portfolio ranking models, and performance attribution Considers stock market developments like decimalization, high frequency trading, and algorithmic trading, and reveals how they align with MPT Companion Website contains Excel spreadsheets that allow you to compute and graph Markowitz efficient frontiers with riskless and risky assets If you want to gain a complete understanding of modern portfolio theory this is the book you need to read.

This book offers a unified treatment of my research in the foundations of expected utility theory from around 1965 to 1980. While parts are new, the presentation draws heavily on published articles and a few chapters in my 1970 monograph on utility theory. The diverse notations and styles of the sources have of course been reconciled here, and their topics arranged in a logical sequence. The two parts of the book take their respective cues from the von Neumann-Morgenstern axiomatization of preferences between risky options and from Savage's foundational treatment of decision making under uncertainty. Both parts are studies in the axiomatics of preferences for decision situations and in numerical representations for preferences. Proofs of the representation and uniqueness theorems appear at the ends of the chapters so as not to impede the flow of the discussion. A few warnings on notation are in order. The numbers for theorems cited within a chapter have no prefix if they appear in that chapter, but otherwise carry a chapter prefix (Theorem 3.2 is Theorem 2 in Chapter 3). All lower case Greek letters refer to numbers in the closed interval from o to 1. The same symbol in different chapters has essentially the same meaning with one major exception: x, y, ... mean quite different things in different chapters. I am indebted to many people for their help and encouragement.

The Conference on "Utility: Theories, Measurements, and Applications" met at the Inn at Pasatiempo in Santa Cruz, California, from June II to 15, 1989. The all-star cast of attendees are listed as authors in the Table of Contents of this book (see p. V), except for Soo Hong Chew and Amos Tversky. The purpose of the conference, and of National Science Foundation Grant No. SES-8823012 that supported it, was to confront proponents of new generalized theories of utility with leading decision analysts com mitted to the implementation, in practice, of the more traditional theory that these new theories reject. That traditional model is variously iden tified in this book as expected utility or subjectively expected utility maximization (EU or SEU for short) and variously attributed to von Neumann and Morgenstern or Savage. I had feared that the conference might consist of an acrimonious debate between Olympian normative theorists uninterested in what people actually do and behavioral modelers obsessed with the cognitive illusions and uninterested in helping people to make wise decisions. I was entirely wrong. The conferees, in two dramatic straw votes at the open ing session, unanimously endorsed traditional SEU as the appropriate normative model and unanimously agreed that people don't act as that model requires. (These votes had a profound impact on my thinking; detail about them and about that impact is located in Chapter 10.