Risk aversion and physical prowess: Prediction,choice and bias

This paper reports on experiments where individuals are asked to make risky decisions for themselves, and to predict the risky decisions of others. Prior research shows that people predict women to be more risk averse than men, a result we confirm. We investigate whether differences in physical prowess underlie actual and perceived gender differences, a hypothesis suggested by both evolutionary and economic theories. Overall we find that perceptions of others’ risk attitudes reflect stereotypes about gender and strength but tend to exaggerate the underlying relationships. Physically stronger and taller people and those perceived as attractive are predicted to be more risk tolerant, while women are perceived to be more risk averse. The impact of gender and physical prowess measures on actual gamble choices is much weaker. Sources of prediction bias are examined, showing that specific characteristics of the target and predictor lead to systematic over-prediction or under-prediction of risk aversion.     

Effects of Outcome and Probabilistic Ambiguity on Managerial Choices

Information ambiguity is prevalent in organizations and likely influences management decisions. This study examines, given imprecise probabilities and outcomes, how managers make choices when they are provided with single-figure benchmarks. Seventy-nine MBA students completed two experiments. We found that, in a decision framed as a decision under certainty involving an ambiguous outcome, the majority of the subjects were ambiguity prone in the loss condition and switched to ambiguity aversion in the gain condition. However, in the presence of probabilistic ambiguity in a decision under risk, this expected switching pattern was shown only when the difference in riskiness between the two choice options (in the loss condition) was perceived to be relatively small. In a companion study, we used a written protocol approach to identify factors that affect decision makers' investment choices when faced with ambiguous outcomes. Protocols frequently mentioned that the ambiguous outcome option was risky, even in the case which was framed as a decision under certainty in the problem statement. In a decision under risk with ambiguous outcomes, the combination of probabilistic risk and outcome ambiguity was seen as even more risky.     

Adjusting risky situations: A theoretical framework and empirical test

Experienced executives frequently try to modify the risky situations they face in order to make them more favorable rather than simply choosing from among available decision options. This article investigates several types of risk adjustments such as trying to influence the situation through bargaining and spending resources, gathering information, developing new options, and consulting one's superiors. A theoretical framework is presented that characterizes different types of adjustments and relates them to variables such as perceived risk, perceived control, perceived responsibility, decisiveness, and risky choice. The framework is tested using experienced decision makers who respond to four simulated risky business decisions.University of British Columbia     

Evidence for multiple strategies in choice under risk

This paper describes an experimental study that yields evidence for the coexistence of two decision strategies of choice under risk. Under the first strategy, choices are made based on aspiration levels – a heuristic that simplifies risky decisions. Under the second strategy, which can be used when aspiration levels are not determinative, choices are made based on preferences for positive skewness. Our model fitting confirms the efficacy of a two-pronged approach that can marshal either strategy depending on specific features of the risky prospects under consideration.     

Learning under compound risk vs. learning under ambiguity – an experiment

We design and conduct an economic experiment to investigate the learning process of agents under compound risk and under ambiguity. We gather data for subjects choosing between lotteries involving risky and ambiguous urns. Agents make decisions in conjunction with a sequence of random draws with replacement, allowing us to estimate the agents’ beliefs at different moments in time. For each type of urn, we estimate a behavioral model for which the standard Bayesian updating model is a particular case. Our findings suggest an important difference in updating behavior between risky and ambiguous environments. Specifically, even after controlling for the initial prior, we find that when learning under ambiguity, subjects significantly overweight the new signal, while when learning under compound risk, subjects are essentially Bayesian.     

Risk taking on behalf of others: The role of social distance

Individuals take decisions on behalf of others in many different contexts. In this paper, we focus on lotteries with negative expected value and study if (and how) risky choices made on behalf of another person differ i) compared to decisions which do not affect anyone else, and ii) depending on the social distance between who makes the decision and who is affected by it. Our results show that social distance (i.e., whether the person affected by one’s decision is an unknown stranger or a friend) is an important determinant when people decide on behalf of others. Moreover, when deciding on behalf of a friend rather than only for themselves or a stranger, average individual behavior is closer to expected value maximization, exhibiting less risk taking. These findings suggest that responsibility for others’ outcome and the empathy gap affect the decision making process, particularly when the social distance is shortened. The results are robust to different feedback frequencies. Controlling for order effects shows that experiencing a decrease in social distance is crucial in activating this mechanism.     

Controlling for initial endowment and experience in binary choice tasks

Learning literature typically assumes that initial attractions to choose each possible alternative are given exogenously. However, evidence shows that current behaviour depends on past experiences. In this paper, we design an experiment to control for the initial experience in decisions from experience by providing decision makers with an exogenous history (successful vs. unsuccessful) prior to initiating the decision task. Moreover, varying the initial endowment level for fixed histories we investigate the income effect. We are also interested in analysing the duration of both effects (history and income). We find significant treatment effects in the sense that more risk taking behaviour is associated with good histories and with low income levels. According to previous literature, our results confirm the transitory nature of both effects, although the duration of the income effect doubles the duration of the history effect. In the long run, risky choice behaviour converges across different treatments.     

Individual vs. couple behavior: an experimental investigation of risk preferences

In this article, we elicit both individuals’ and couples’ preferences assuming prospect theory (PT) as a general theoretical framework for decision under risk. Our experimental method, based on certainty equivalents, allows to infer measurements of utility and probability weighting at the individual level and at the couple level. Our main results are twofold. First, risk attitude for couples is compatible with PT and incorporates deviations from expected utility similar to those found in individual decision making. Second, couples’ attitudes towards risk are found to be consistent with a mix of individual attitudes, women being more influent on couples’ preferences at low probability levels.     

Testing the ‘standard’ model of stochastic choice under risk

Models of stochastic choice are intended to capture the substantial amount of noise observed in decisions under risk. We present an experimental test of one model, which many regard as the default—the Basic Fechner model. We consider one of the model’s key assumptions—that the noise around the subjective value of a risky option is independent of other features of the decision problem. We find that this assumption is systematically violated. However the main patterns in our data can be accommodated by a more recent variant of the Fechner model, or within the random preference framework.     

Double or nothing?! Small groups making decisions under risk in “Quiz Taxi”

This paper investigates the behavior of contestants in the game show “Quiz Taxi” when faced with the decision whether to bet the winnings they have acquired on a final “double or nothing” question. The decision in this natural experiment is made by groups of two or three persons. This setup enables the decision-making process to be studied with regard to group and communication characteristics. The contestants show fairly risk averse behavior. There is also a significant heterogeneity in attitude to risk. In particular, all-female groups are much less likely to go for the risky option. Furthermore, decision-making behavior appears to vary across differently composed groups and prior performance. The study also documents the importance of discussions: The propensity to gamble increases with discussion length, and the correlation between communication content and the final choice is strong, indicating that time and subjective context are important features of decisions made under risk.     

When risky decisions generate externalities

Many risky decisions generate either positive externalities (e.g., opening a small business, engaging in research and development, vaccinating) or negative externalities (e.g., smoking, reckless driving, unprotected sex). I develop a new experimental framework for evaluating risk tolerance when risky decisions that generate externalities by modifying the allocation task of Gneezy and Potters (1997). In the ‘risk with externalities’ framework, for each unit increase in a risky allocation, an external cost or benefit is imposed upon a group member. I further vary the magnitude of the external effect to investigate the sensitivity of risk taking to the marginal external effect. Results indicate that risky decisions are driven by a combination of social and non-social factors. When individuals both impose and receive externalities, the preferred level of risk taking is lower if the externality is negative, regardless of the magnitude of the marginal external effect. Risk taking is then further affected by the magnitude of the marginal external effect. For individuals who only impose externalities, behavior is consistent with a disutility from imposing harm (but not a sensitivity to the magnitude of the external effect). For those who only receive externalities, individuals increase (decrease) their risky allocation when they are in a decision environment where they receive external benefits (costs). Additional treatments suggest that results are consistent with decreasing relative risk aversion plus an additional disutility from either imposing or receiving harmful externalities.

     

Subjective Probability Weighting and the Discovered Preference Hypothesis

Numerous studies have convincingly shown that prospect theory can better describe risky choice behavior than the classical expected utility model because it makes the plausible assumption that risk aversion is driven not only by the degree of sensitivity toward outcomes, but also by the degree of sensitivity toward probabilities. This article presents the results of an experiment aimed at testing whether agents become more sensitive toward probabilities over time when they repeatedly face similar decisions, receive feedback on the consequences of their decisions, and are given ample incentives to reflect on their decisions, as predicted by Plott’s Discovered Preference Hypothesis (DPH). The results of a laboratory experiment with N = 62 participants support this hypothesis. The elicited subjective probability weighting function converges significantly toward linearity when respondents are asked to make repeated choices and are given direct feedback after each choice. Such convergence to linearity is absent in an experimental treatment where respondents are asked to make repeated choices but do not experience the resolution of risk directly after each choice, as predicted by the DPH. I thank Peter P. Wakker for useful comments and suggestions.     

Gender, Financial Risk, and Probability Weights

Women are commonly stereotyped as more risk averse than men in financial decision making. In this paper we examine whether this stereotype reflects gender differences in actual risk-taking behavior by means of a laboratory experiment with monetary incentives. Gender differences in risk taking may be due to differences in valuations of outcomes or in probability weights. The results of our experiment indicate that value functions do not differ significantly between men and women. Men and women differ in their probability weighting schemes, however. In general, women tend to be less sensitive to probability changes. They also tend to underestimate large probabilities of gains more strongly than do men. This effect is particularly pronounced when the decisions are framed in investment terms. As a result, women appear to be more risk averse than men in specific circumstances.     

Choosing a gambling partner: testing a model of mutual insurance in the lab

In this study, we investigate how economic agents choose gambling partners and how paired risky choices differ from individual ones. To this aim, we develop a simple model and design a laboratory experiment that allows us to compare individual versus paired decisions across two treatments, where pairs are, respectively, exogenously and endogenously formed. In both treatments, paired subjects decide individually and independently how to allocate their wealth over a portfolio of lotteries and fully commit to share any winnings. The main result from our experiment is that whenever agents are allowed to choose a gambling partner they decide to team up with other agents who display the same degree of risk aversion as themselves. Moreover, paired choices consistently involve higher risk taking than individual choices. This finding is more evident when information on subjects’ risk attitudes is made available and when subjects team up in homogeneous pairs, thereby confirming that subjects successfully exploit the benefits of mutual insurance.     

The Interaction Between the Demands for Insurance and Insurable Assets

Holding more of the riskless asset and insuring the risky asset are two ways to reduce portfolio risk. These methods can be employed jointly. As a result, the amount of insurance selected to indemnify against possible losses from holding a risky asset depends, in general, on the quantities of the risky and riskless assets held in the portfolio, and vice versa. In decision models where expected utility is maximized, relatively little has been done to integrate these two decisions into a single model. Such a model is formulated in this paper and the interaction between the demand for insurance and the demand for an insurable risky asset is examined.     

Estimating individual and group preference functionals using experimental data

In this paper, the empirical performance of several preference functionals is assessed using individual and group experimental data. We investigate if there is a risky choice theory that fits group decisions better than alternative theories, and if there are significant differences between individual and group choices. Experimental findings reported in this paper provide answers to both of those questions showing that expected utility gains a “winning” position over higher-level functionals (we considered disappoint aversion and two variants of rank-dependent utility) when risky choices are undertaken by individuals as well as by small groups. However, in the group experiment, alternatives (and, most notably, disappoint aversion) improve their relative performance, a fact that hints at the existence of differences between individual and group choices. We interpreted this result as evidence that feelings-like disappointment aversion become stronger in group decision.     

Myopic risk-seeking: The impact of narrow decision bracketing on lottery play

In two experiments conducted with low-income participants, we find that individuals are more likely to buy state lottery tickets when they make several purchase decisions one-at-a-time, i.e. myopically, than when they make one decision about how many tickets to purchase. These results extend earlier findings showing that “broad bracketing” of decisions encourages behavior consistent with expected value maximization. Additionally, the results suggest that the combination of myopic decision making and the “peanuts effect”—greater risk seeking for low stakes than high stakes gambles—can help explain the popularity of state lotteries.

Who REALLY Wants to be a Millionaire? Gender Differences in Game Show Contestant Behavior Under Risk*

Objective. On the popular game show Who Wants to be a Millionaire men appear to average higher winnings than women. This article investigates potential reasons, including different uses of information sources (lifelines) and different perceptions of risk. Method. We analyzed the decisions and resultant winnings of 164 contestants (95 men and 69 women) over 42 episodes of the show. Results. Gender‐based tests of Kahneman and Tversky's prospect theory demonstrated evidence of gender differences in the certainty effect and suggested the counterintuitive conclusion that men are rewarded for acting slightly more cautiously than do women. Conclusions. These gender differences may be owing to self‐selection of contestants, particularly for women, and to different goals: whereas men play to maximize their winnings, women may be less concerned with profit than with the experience as a whole. These findings suggest that examination of gender‐related behavior in other risky, high‐profile contexts may be worthwhile.     

Examination of the Child Protective Services Decision-Making Context with Implications for Decision Support System Design

Abstract

The general perception of Child Protective Services (CPS) decision making is that it is inconsistent and prone to error. As a result, risk assessment instruments were developed to enable investigators to make better decisions. The present study uses a qualitative approach with an explicit theoretical framework pertinent to management information systems and decision support system design to examine the context in which investigators operate and make decisions. The resulting information can be used to determine design requirements that would improve the experience of using a risk assessment instrument that serves as a decision support system (DSS) for CPS investigators.