
on Utility Models and Prospect Theory 
By:  Daniel Friedman (Dept. Economics, UC Santa Cruz; CESifo); Shyam Sunder (Yale School of Management) 
Abstract:  Most theories of risky choice postulate that a decision maker maximizes the expectation of a Bernoulli (or utility or similar) function. We tour 60 years of empirical search and conclude that no such functions have yet been found that are useful for outofsample prediction. Nor do we find practical applications of Bernoulli functions in major riskbased industries such as finance, insurance and gambling. We sketch an alternative approach to modeling risky choice that focuses on potentially observable opportunities rather than on unobservable Bernoulli functions. 
Keywords:  Expected utility, Risk aversion, St. Petersburg Paradox, Decisions under uncertainty, Option theory 
JEL:  C91 C93 D11 D81 G11 G12 G22 L83 
Date:  2011–08 
URL:  http://d.repec.org/n?u=RePEc:cwl:cwldpp:1819&r=upt 
By:  James Andreoni; Charles Sprenger 
Abstract:  There is convincing experimental evidence that Expected Utility fails, but when does it fail, how severely, and for what fraction of subjects? We explore these questions using a novel measure we call the uncertainty equivalent. We find Expected Utility performs well away from certainty, but fails near certainty for about 40% of subjects. Comparing nonExpected Utility theories, we strongly reject Prospect Theory probability weighting, we support disappointment aversion if amended to allow violations of stochastic dominance, but find the uv model of a direct preference for certainty the most parsimonious approach. 
JEL:  D81 
Date:  2011–08 
URL:  http://d.repec.org/n?u=RePEc:nbr:nberwo:17342&r=upt 
By:  Stefan T. Trautmann; Ulrich Schmidt 
Abstract:  There is a large literature showing that willingnesstoaccept (WTA) is usually much higher than willingnesstopay (WTP) in empirical studies although they should be roughly equal according to traditional economic theory. A second stream of literature shows that people are typically ambiguity averse, i.e. they prefer lotteries with known probabilities over lotteries with unknown ones. Our study combines both streams of literature and analyzes whether there is an interaction between the WTPWTA disparity and ambiguity aversion 
Keywords:  WTPWTA disparity, ambiguity aversion, comparative ignorance 
JEL:  C91 D81 
Date:  2011–08 
URL:  http://d.repec.org/n?u=RePEc:kie:kieliw:1727&r=upt 
By:  Stephen A. Ross 
Abstract:  We can only estimate the distribution of stock returns but we observe the distribution of risk neutral state prices. Risk neutral state prices are the product of risk aversion – the pricing kernel – and the natural probability distribution. The Recovery Theorem enables us to separate these and to determine the market’s forecast of returns and the market’s risk aversion from state prices alone. Among other things, this allows us to determine the pricing kernel, the market risk premium, the probability of a catastrophe, and to construct model free tests of the efficient market hypothesis. 
JEL:  E1 G0 G11 G12 
Date:  2011–08 
URL:  http://d.repec.org/n?u=RePEc:nbr:nberwo:17323&r=upt 
By:  Jonathan E. Alevy (Department of Economics, University of Alaska Anchorage) 
Abstract:  After Ellsberg’s thought experiments brought focus to the relevance of missing information for choice, extensive efforts have been made to understand ambiguity theoretically and empirically (Ellsberg 1961). Fox and Tversky (1995) make an important contribution to understanding behavioral responses to ambiguity. In an individual choice setting they demonstrate that an aversion to ambiguous lotteries arises only when a comparison to unambiguous lotteries is available. The current study advances this literature by exploring the importance of Fox and Tversky’s finding for market outcomes and finds support for their Comparative Ignorance Hypothesis in the market setting. 
Keywords:  ambiguity, asset market experiment, comparitive ignorance 
JEL:  C91 C92 D81 G12 
Date:  2011 
URL:  http://d.repec.org/n?u=RePEc:ala:wpaper:201104&r=upt 
By:  Robert J. Barro; José F. Ursua 
Abstract:  The potential for rare macroeconomic disasters may explain an array of assetpricing puzzles. Our empirical studies of these extreme events rely on longterm data now covering 28 countries for consumption and 40 for GDP. A baseline model calibrated with observed peaktotrough disaster sizes accords with the average equity premium with a reasonable coefficient of relative risk aversion. High stockprice volatility can be explained by incorporating timevarying longrun growth rates and disaster probabilities. Businesscycle models with shocks to disaster probability have implications for the cyclical behavior of asset returns and corporate leverage, and international versions may explain the uncoveredinterestparity puzzle. Richer models of disaster dynamics allow for transitions between normalcy and disaster, bring in postcrisis recoveries, and use the full time series on consumption. Potential future research includes applications to longterm economic growth and environmental economics and the use of stockprice options and other variables to gauge timevarying disaster probabilities. 
JEL:  E01 E44 G12 G15 
Date:  2011–08 
URL:  http://d.repec.org/n?u=RePEc:nbr:nberwo:17328&r=upt 
By:  Miryana Grigorova (LPMA  Laboratoire de Probabilités et Modèles Aléatoires  CNRS : UMR7599  Université Pierre et Marie Curie  Paris VI  Université Paris Diderot  Paris 7) 
Abstract:  In an analogous way to the classical case of a probability measure, we extend the notion of an increasing convex (concave) stochastic dominance relation to the case of a normalised monotone (but not necessarily additive) set function also called a capacity. We give different characterizations of this relation establishing a link to the notions of distribution function and quantile function with respect to the given capacity. The Choquet integral is extensively used as a tool. We state a new version of the classical upper (resp. lower) HardyLittlewood's inequality generalized to the case of a continuous from below concave (resp. convex) capacity. We apply our results to a financial optimization problem whose constraints are expressed by means of the increasing convex stochastic dominance relation with respect to a capacity. 
Keywords:  stochastic orderings; increasing convex stochastic dominance; Choquet integral; quantile function with respect to a capacity; stoploss ordering; Choquet expected utility; distorted capacity; generalized HardyLittlewood's inequalities; distortion risk measure; ambiguity 
Date:  2011–08–15 
URL:  http://d.repec.org/n?u=RePEc:hal:wpaper:hal00614716&r=upt 
By:  Jaume García Segarra (Fundamentos del Análisis Económico (Economics Department), Universitat Jaume I); Miguel Ginés Vilar (Fundamentos del Análisis Económico (Economics Department), Universitat Jaume I) 
Abstract:  We propose and characterize a new solution for problems with asymmetric bargaining power among the agents that we named weighted proportional losses solution. It is specially interesting when agents are bargaining under restricted probabilistic uncertainty. The weighted proportional losses assigns to each agent losses proportional to her ideal utility and also proportional to her bargaining power. This solution is always individually rational, even for 3 or more agents and it can be seen as the normalized weighted equal losses solution. When bargaining power among the agents is equal, the weighted proportional losses solution becomes the KalaiSmorodinsky solution. We characterize our solution in the basis of restricted monotonicity and restricted concavity. A consequence of this result is an alternative characterization of KalaiSmorodinsky solution which includes contexts with some kind of uncertainty. Finally we show that weighted proportional losses solution satisfyies desirable properties as are strong Pareto optimality for 2 agents and continuity also fulfilled by KalaiSmorodinsky solution, that are not satisfied either by weighted or asymmetric KalaiSmorodinsky solutions. 
Date:  2011–08–01 
URL:  http://d.repec.org/n?u=RePEc:gra:wpaper:10/21&r=upt 
By:  Jessica A. Wachter; Missaka Warusawitharana 
Abstract:  We examine the evidence on excess stock return predictability in a Bayesian setting in which the investor faces uncertainty about both the existence and strength of predictability. Departing from previous studies, we do not assume that the regressor is strictly exogenous. When we apply our methods to the dividendprice ratio, we find that even investors who are quite skeptical about the existence of predictability sharply modify their views in favor of predictability when confronted by the historical time series of returns and predictor variables. We find that taking into account the stochastic properties of the regressor has a substantial impact on the investor's inference about returns. 
JEL:  C11 C22 G11 
Date:  2011–08 
URL:  http://d.repec.org/n?u=RePEc:nbr:nberwo:17334&r=upt 