Stronger Utility

Empirical research often requires a method how to convert a deterministic economic theory into an econometric model. A popular method is to add a random error term on the utility scale. This method, however, violates stochastic dominance. A modification of this method is proposed to avoid violations of dominance. The modified model compares favorably to other existing models in terms of goodness of fit to experimental data. The modified model can rationalize the preference reversal phenomenon. An intuitive axiomatic characterization of the modified model is provided. Important microeconomic concept of risk aversion is well-defined in the modified model.Decision Theory, Probabilistic Choice, Stochastic Dominance, Strong Utility, Risk Aversion

Violations of betweenness or random errors?

A betweenness axiom states that if A and B are equally good then a mixture of A and B is equally good as well. This note demonstrates that the violations of the betweenness axiom documented in several experimental studies can be alternatively attributed to the effect of random errors

Violations of betweenness and choice shifts in groups

In decision theory, the betweenness axiom postulates that a decision maker who chooses an alternative A over another alternative B must also choose any probability mixture of A and B over B itself and can never choose a probability mixture of A and B over A itself. The betweenness axiom is a weaker version of the independence axiom of expected utility theory. Numerous empirical studies documented systematic violations of the betweenness axiom in revealed individual choice under uncertainty. This paper shows that these systematic violations can be linked to another behavioral regularity\u2014choice shifts in a group decision making. Choice shifts are observed if an individual faces the same decision problem but makes a different choice when deciding alone and in a group

Measuring Risk Attitudes Controlling for Personality Traits*

Abstract: This study measures risk attitudes using two paid experiments: the Holt and Laury (2002) procedure and a variation of the game show Deal or No Deal. The participants also completed a series of personality questionnaires developed in the psychology literature including the risk domains of Weber, Blais, and Betz (2002). As in previous studies risk attitudes vary within subjects across elicitation methods. However, this variation can be explained by individual personality traits. Specifically, subjects behave as though the Holt and Laury task is an investment decision while the Deal or No Deal task is a gambling decision

Efficient elicitation of utility and probability weighting functions

Elicitation methods in decision making under risk allow a researcher to infer thensubjective utilities of outcomes as well as the subjective weights of probabilities from observed preferences of an individual. An optimally efficient elicitation method is proposed, which takes into account the inevitable distortion of preferences by random errors and minimizesnthe effect of such errors on the inferred utility and probability weighting functions. Under mildnassumptions, the optimally efficient method for eliciting utilities (weights) of many outcomes (probabilities) is the following three-stage procedure. First, a probability is elicited whose subjective weight is one half. Second, an individual's utility function is elicited through the midpoint chaining certainty equivalent method employing the probability elicited at the first stagenas an input. Finally, an individual's probability weighting function is elicited through the probability equivalent method

Probabilistic Choice and Stochastic Dominance

This paper presents an axiomatic model of probabilistic choice under risk. In this model, when it comes to choosing one lottery over another, each alternative has a chance of being selected, unless one lottery stochastically dominates the other. An individual behaves as if he compares lotteries to a reference lottery—a least upper bound or a greatest lower boundnin terms of weak dominance. The proposed model is compatible with several well-known violations of expected utility theory such as the common ratio effect and the violations of the betweenness. Necessary and sufficient conditions for the proposed model are completeness, weak stochastic transitivity, continuity, common consequence independence,noutcome monotonicity, and odds ratio independence

Reverse Common Ratio Effect

The results of a new experimental study reveal highly systematic violations ofnexpected utility theory. The pattern of these violations is exactly the opposite of thenclassical common ratio effect discovered by Allais (1953). Two recent decision theories—nstochastic expected utility theory (Blavatskyy, 2007) and perceived relative argumentnmodel (Loomes, 2008)—predicted the existence of a reverse common ratio effect. However, these theories can rationalize only one part of the new experimental data reported in this paper. The other part appears to be neither predicted by existing theories nor documented in the existing empirical studies

Stochastic Choice Under Risk

An individual makes random errors when evaluating the expected utility of a risky lottery. Errors are symmetrically distributed around zero as long as an individual does not make transparentnmistakes such as choosing a risky lottery over its highest possible outcome for certain. This stochastic decision theory explains many well-known violations of expected utility theory such as the fourfold pattern of risk attitudes, the discrepancy between certainty equivalent and probability equivalent elicitation methods, the preference reversal phenomenon, the generalizedncommon consequence effect (the Allais paradox), the common ratio effect and the violations of the betweenness

Preference Reversals and Probabilistic Choice

Preference reversals occur when different (but formally equivalent) elicitation methodsnreveal conflicting preferences over two alternatives. This paper shows that when people have fuzzy preferences i.e. when they choose in a probabilistic manner, their observed decisions can generate systematic preference reversals. A simple model of probabilistic choice and valuation can account for a higher incidence of standard (nonstandard) preference reversals for certainty (probability) equivalents and it can also rationalize the existence of strong reversals. An important methodological contribution of the paper is a new definition of a probabilistic certainty/probability equivalent of a risky lottery