The Effects of Statistical Information on Risk- and Ambiguity-Attitudes, and on Rational Insurance Decisions

This is a preprint of an article to be published in Management ScienceThis paper examines the effects of statistical information about risks on risk attitudes and demand for insurance. A descriptive purpose is to obtain new insights into risk and ambiguity attitudes of the general public. A prescriptive purpose is to provide recommendations for the provision of risk information to individuals so as to help them choose their most preferred options. In an experiment, N = 476 clients of a Dutch health insurance company were given various forms of statistical information about health expenses. Average population-cost information generally increased the willingness to take insurance. Own past-costs information differentiated betwee individuals, increasing the willingness to take insurance for high-cost and risk averse clients but not for others. Detailed cost information reinforced the effects of total-cost information. Prescriptively, the drawback of adverse selection must be weighed against a desirable interaction with risk attitude, increased customer satisfaction, and increased cost awareness. Descriptively, ambiguity preference was found rather than aversion, and no risk aversion was found for loss outcomes. Both findings, obtained in a natural decision context, deviate from traditional views in risk theory but agree with prospect theory

Comment on Noll and Krier, "Some Implications of Cognitive Psychology for Risk Regulation"

We have known about systematic violations of the expected utility (EU) theory of choice for almost forty years, since Maurice Allais got Jimmie Savage to violate his own "sure-thing principle" (or "independence axiom") while making hypothetical choices over lunch in Paris. Savage was victimized by some combination of wine and intuition. The wine's effect is gone, but the intuition is not: devotion to EU sometimes produces unappealing choices

Risk attitudes and Medicare Part D enrollment decisions

The new Medicare Part D program provides prescription drug coverage for older Americans through highly subsidized and tightly regulated plans offered by private insurance firms. For most eligible individuals without coverage from other sources, obtaining Part D coverage would be rational, but it requires active enrollment and plan choice decisions. We investigate if non-enrollment in Medicare Part D can partly be explained by risk aversion. Data are taken from a national online survey conducted just after the introduction Part D. The survey included a context-free and a context-related hypothetical lottery to measure an individual’s attitude towards risk. Respondents who are risk tolerant according to these measures were significantly less likely to enroll in Part D. We also illustrate that hypothetical choice questions designed to elicit risk attitudes are subject to reference-point effects. Even minor differences in the priming of respondents can result in potentially misleading conclusions about the role of risk aversion in the insurance decisions

Risk and Rationality: Uncovering Heterogeneity in Probability Distortion

It has long been recognized that there is considerable heterogeneity in individual risk taking behavior but little is known about the distribution of risk taking types. We present a parsimonious characterization of risk taking behavior by estimating a finite mixture regression model for three different experimental data sets, two Swiss and one Chinese, over a large number of real gains and losses. We find two distinct types of individuals: In all three data sets, the choices of roughly 80% of the subjects exhibit significant deviations from rational probability weighting consistent with prospect theory. 20% of the subjects weight probabilities linearly and behave essentially as expected value maximizers. Moreover, the individuals are assigned to one of these two groups with probabilities of close to one resulting in a low measure of entropy. The reliability and robustness of our classification suggest using a mix of preference theories in applied economic modeling.individual risk taking behavior, latent heterogeneity, finite mixture regression models

Reaction to Uncertainty and Market Mechanism:Experimental Evidence

Abstract Much of the evidence supporting the Ellsberg's paradox comes from experiments on individual choice and judgement. In this study, we address the issue whether, in market experiments, there is a tendency for anomalous behaviour to disappear or to be reduced as a consequence of market experience and feedback. We empirically test the validity of this assumption by running an auction market for the sale of both risky and uncertain prospects. We compare bidding behaviour and prices in market-like settings with valuations obtained from individual pricing tasks. We conclude that, with the repetition of the market experience, there is a tendency for subjective expected utility to perform better. However, economists' general assumption that, in laboratory experiments, poor performance of SEU is due to the lack of financial incentives or to the lack of market-like settings is by no means supported by our data.

A Note on the Equivalence of Rationalizability Concepts in Generalized Nice Games

Moulin (1984) describes the class of nice games for which the solution concept of point-rationalizability coincides with iterated elimination of strongly dominated strategies. As a consequence nice games have the desirable property that all rationalizability concepts determine the same strategic solution. However, nice games are characterized by rather strong assumptions. For example, only single-valued best responses are admitted and the individual strategy sets have to be convex and compact subsets of the real line R1. This note shows that equivalence of all rationalizability concepts can be extended to multi-valued best response correspondences. The surprising finding is that equivalence does not hold for individual strategy sets that are compact and convex subsets of Rn with n>1.

Social anchor effects in decision-making under ambiguity

I experimentally examine whether feedback about others' choices provides an anchor for decision-making under ambiguity. In a between-subjects design I vary whether subjects learn choices made individually by a "peer" in a first part when facing the same task a second time, and whether prospects are defined over gains or losses. My key findings are that the relative ambiguity attitude (compared to the peer's) significantly matters for shifts in individual attitudes, and that dynamics considerably differ between gain and loss domains. For gains, learning to be comparably ambiguity averse increases the likelihood for such shifts, relative to the individual condition; for losses, this likelihood decreases only if peers learn to exhibit exactly the same attitude. Further, I observe imitative shifts towards the peer's attitude in the gain domain, but only towards neutrality in the loss domain. Shifts towards neutrality for losses also appear significant without social anchor suggesting that ambiguity seeking might not be particularly robust. Moreover, cognitive ability positively correlates to shifts towards neutrality in the gain domain, but has no impact in the loss domain

Ambiguity and Social Interaction

We examine the impact of ambiguity on economic behaviour. We present a relatively non-technical account of ambiguity and show how it may be applied in economics. Optimistic and pessimistic responses to ambiguity are formally modelled. We show that pessimism has the effect of increasing (decreasing) equilibrium prices under Cournot (Bertrand) competition. We also examine the effects of ambiguity on peace processes. It is shown that ambiguity can act to select equilibria in coordination games with multiple equilibria. Some comparative statics results are derived for the impact of ambiguity in games with strategic complements.

Risk attitudes and Medicare Part D enrollment decisions

The new Medicare Part D program provides prescription drug coverage for older Americans through highly subsidized and tightly regulated plans offered by private insurance firms. For most eligible individuals without coverage from other sources, obtaining Part D coverage would be rational, but it requires active enrollment and plan choice decisions. We investigate if non-enrollment in Medicare Part D can partly be explained by risk aversion. Data are taken from a national online survey conducted just after the introduction Part D. The survey included a context-free and a context-related hypothetical lottery to measure an individual’s attitude towards risk. Respondents who are risk tolerant according to these measures were significantly less likely to enroll in Part D. We also illustrate that hypothetical choice questions designed to elicit risk attitudes are subject to reference-point effects. Even minor differences in the priming of respondents can result in potentially misleading conclusions about the role of risk aversion in the insurance decisions.Risk aversion; Medicare Part D; heterogeneous preferences; insurance demand; survey design

Decisions under Risk, Uncertainty and Ambiguity: Theory and Experiments

I combine theory, experiments and econometrics to undertake the task of disentangling the subtleties and implications of the distinction between risk, uncertainty and ambiguity. One general conclusion is that the elements of this methodological trilogy are not equally advanced. For example, new experimental tools must be developed to adequately test the predictions of theory. My dissertation is an example of this dynamic between theoretical and applied economics