http://repub.eur.nl/res/concept/jel-C60/ Recent publications classified by JEL Code C60 en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/23265/ 2011-06-01T00:00:00Z Preference foundations give necessary and sufficient conditions for a decision model, stated directly in terms of the empirical primitive: the preference relation. For the most popular descriptive model for decision making under risk and uncertainty today, prospect theory, preference foundations have as yet been provided only for prospects taking finitely many values. In applications, however, prospects often are complex and involve infinitely many values, as in normal and lognormal distributions. This paper provides a preference foundation of prospect theory for such complex prospects. We allow for unbounded utility and only require finite additivity of the underlying probability distributions, leaving the restriction to countably additive distributions optional. As corollaries, we generalize previously obtained preference foundations for special cases of prospect theory (rank-dependent utility and Choquet expected utility) that all required countable additivity. We now obtain genuine generalizations of de Finetti’s and Savage’s finitely additive setups to unbounded utility. Kothiyal, A. Spinu, V. http://repub.eur.nl/res/pub/22985/ 2008-03-01T00:00:00Z This paper introduces a new preference condition that can be used to justify (or criticize) expected utility. The approach taken in this paper is an alternative to Savage's, and is accessible to readers without a mathematical background. It is based on a method for deriving comparisons of tradeoffs from ordinal preferences. Our condition simplifies previously-published tradeoff conditions, and at the same time provides more general and more powerful tools to specialists. The condition is more closely related to empirical methods for measuring utility than its predecessors. It provides a unifying tool for qualitatively testing, quantitatively measuring, and normatively justifying expected utility. Köbberling, V. http://repub.eur.nl/res/pub/11073/ 2007-01-01T00:00:00Z Koopmans provided a well-known preference foundation for discounted utility, the most widely used model for intertemporal optimization. There were, however, some problems in his analysis. For example, there was an unforeseen implication of bounded utility. For some domains solutions have been advanced in the literature, primarily when particular production processes impose time-dependent restrictions on consumption. This paper completely resolves the problems mentioned, irrespective of what the restrictions on consumption are. It obtains complete flexibility concerningt he utility functions that can be used and concerning the conceivable economic growth. This paper, thus, provides a complete preference foundation of discounted utility, and clarifies the appeal of Koopmans’ intuitive axioms. Bleichrodt, H. Rohde, K.I.M. Wakker, P.P. http://repub.eur.nl/res/pub/11077/ 2007-01-01T00:00:00Z The commonly used hyperbolic and quasi-hyperbolic discount functions imply decreasing impatience, which is the prevailing empirical phenomenon in intertemporal choice, in particular for aggregate behavior. At the individual level there is much variation, however, and there will always be some individuals who exhibit increasing impatience. Hence, to fit data at the individual level, new discount functions are needed. This paper introduces such functions, with constant absolute (CADI) or constant relative (CRDI) decreasing impatience. These functions can accommodate any degree of decreasing or increasing impatience, which makes them sufficiently flexible for analyses at the individual level. The CADI and CRDI discount functions are the analogs of the well known CARA and CRRA utility functions for decision under risk. Bleichrodt, H. Rohde, K.I.M. Wakker, P.P. http://repub.eur.nl/res/pub/6922/ 2005-09-06T00:00:00Z The first three factors resulting from a principal components analysis of term structure data are in the literature typically interpreted as driving the level, slope and curvature of the term structure. Using slight generalisations of theorems from total positivity, we present sufficient conditions under which level, slope and curvature are present. These conditions have the nice interpretation of restricting the level, slope and curvature of the correlation surface. It is proven that the Schoenmakers-Coffey correlation matrix also brings along such factors. Finally, we formulate and corroborate our conjecture that the order present in correlation matrices causes slope. Lord, R. Pelsser, A.A.J. http://repub.eur.nl/res/pub/8205/ 2005-01-01T00:00:00Z To a considerable extent, risk aversion as it is commonly observed is caused by loss aversion. Several indexes of loss aversion have been proposed in the literature. The one proposed in this paper leads to a clear decomposition of risk attitude into three distinct components: basic utility, probability weighting, and loss aversion. The index is independent of the unit of payment. The main theorem shows how the indexes of different decision makers can be compared through observed choices. Köbberling, V. Wakker, P.P. http://repub.eur.nl/res/pub/23024/ 2002-12-01T00:00:00Z Most empirical studies of rank-dependent utility and cumulative prospect theory have assumed power utility functions, both for gains and for losses. As it turns out, a remarkably simple preference foundation is possible for such models: Tail independence (a weakening of comonotonic independence which underlies all rank-dependent models) together with constant proportional risk aversion suffice, in the presence of common assumptions (weak ordering, continuity, and first stochastic dominance), to imply these models. Thus, sign dependence, the different treatment of gains and losses, and the separation of decision weights and utility are obtained free of charge. Wakker, P.P. Zank, H. http://repub.eur.nl/res/pub/130/ 2001-11-30T00:00:00Z We derive empirical tests for the mean-variance efficiency of a given portfolio. The tests can be computed using straightforward linear programming, and they give substantial flexibility in modeling the investment possibilities. Using this test, we can reject the hypothesis that the S&P 500 index is mean-variance efficient relative to the 25 Fama and French (1993) equity portfolios. Post, G.T. http://repub.eur.nl/res/pub/23081/ 1999-08-01T00:00:00Z Classical foundations of expected utility were provided by Ramsey, de Finetti, von Neumann and Morgenstern, Anscombe and Aumann, and others. These foundations describe preference conditions to capture the empirical content of expected utility. The assumed preference conditions, however, vary among the models and a unifying idea is not readily transparent. Providing such a unifying idea is the purpose of this paper. The mentioned derivations have in common that a cardinal utility index for outcomes, independent of the states and probabilities, can be derived. Characterizing that feature provides the unifying idea of the mentioned models. Wakker, P.P. Zank, H. http://repub.eur.nl/res/pub/23101/ 1996-12-01T00:00:00Z A method is given to extend demand functions to new commodities under preservation of the cycle number, i.e. the minimal length of a preference cycle revealed by the demand function. Thus, Gale's (Economica, N.S., 1960, 27, 348–354) demand function that shows that the weak axiom of revealed preference does not imply the strong axiom of revealed preference for three commodities can be extended to more than three commodities. Also Shafer's (Journal of Economic Theory, 1977, 16, 293–309) result, that arbitrarily high cycle numbers exist for three commodities, can now be extended to any number of commodities larger than three. This completely settles a question raised by Samuelson (Economica, N.S., 1953, 20, 1–9). Peters, H.J.M. Wakker, P.P. http://repub.eur.nl/res/pub/23106/ 1996-12-01T00:00:00Z This paper compares classical expected utility with the more general rank-dependent utility models. It shows that the difference between the sure-thing principle for preferences of expected utility and its comonotonic generalization in rank-dependent utility provides the exact demarcation between expected utility and rank-dependent models. Wakker, P.P. http://repub.eur.nl/res/pub/23129/ 1994-02-01T00:00:00Z The only examples available in the literature to show that the Weak Axiom of Revealed Preference does not imply the Strong Axiom of Revealed Preference, the examples of Gale and Shafer, apply only to the case of three commodities. This paper constructs examples for four or more commodities. Peters, H.J.M.