Gender,risk and stereotypes

This paper reports results from an economic experiment where respondents are asked to make choices between risky outcomes for themselves and others. We investigate whether subjects’ own risk preferences and gender stereotypes are reflected in the predictions they make for the risk preferences of others and the way this occurs. When predicting other people’s risk preferences, the respondents tend to use a combination of their own risk preferences and stereotypes. Moreover, when making risky choices for others, the respondents generally use a combination of their own risk preferences and their average predicted risk preference of the targeted group.

Can ranking techniques elicit robust values?

This paper reports two experiments which examine the use of ranking methods to elicit ‘certainty equivalent’ values. It investigates whether such methods are able to eliminate the disparities between choice and value which constitute the ‘preference reversal phenomenon’ and which thereby pose serious problems for both theory and policy application. The results show that ranking methods are vulnerable to distorting effects of their own, but that when such effects are controlled for, the preference reversal phenomenon, previously so strong and striking, is very considerably attenuated.

Predicted risk perception and risk-taking behavior: The case of impaired driving

Research suggests an association between risk perception and risk-taking behavior in a variety of contexts. There is empirical evidence that perceived risk is generally biased and that perception of risk influences behavior. Perception of risk can be endogenous. It is therefore more appropriate to instrument risk perception. This article studies the perception of the risks associated with impaired driving and the relation between predicted risk perception and driving behavior. We survey a sample of license-holders, half of whom are drivers with a past conviction for impaired driving, the other half or control group without such conviction. Predicted perceptual biases are shown to influence actual driving behavior.

Probability weighting and the ‘level’ and ‘spacing’ of outcomes: An experimental study over losses

The main goal of the experimental study described in this paper is to investigate the sensitivity of probability weighting to the payoff structure of the gambling situation—namely the level of consequences at stake and the spacing between them—in the loss domain. For that purpose, three kinds of gambles are introduced: two kinds of homogeneous gambles (involving either small or large losses), and heterogeneous gambles involving both large and small losses. The findings suggest that at least for moderate/high probability of loss do both ‘level’ and ‘spacing’ effects reach significance, with the impact of ‘spacing’ being both opposite to and stronger than the impact of ‘level’. As compared to small-loss gambles, large-loss gambles appear to enhance probabilistic optimism, while heterogeneous gambles tend to increase pessimism.

Paying for permanence: Public preferences for contaminated site cleanup

We use conjoint choice questions to investigate the preferences of people in four cities in Italy for income and future/permanent mortality risk reductions delivered by contaminated site remediation policies. The VSL is €5.6 million for an immediate risk reduction. If the risk reduction takes place 20 years from now, the implied VSL is €1.26 million. Respondents’ implicit discount rate is 7%. The VSL depends on respondent characteristics, familiarity with contaminated sites, concern about the health effects of exposure to toxicants, having a family member with cancer, perceived usefulness of public programs and beliefs about the goals of government remediation programs.

The value of mortality risk reductions in Delhi,India

We interviewed commuters in Delhi, India, to estimate their willingness to pay (WTP) to reduce their risk of dying in road traffic accidents in three scenarios that mirror the circumstances under which traffic fatalities occur in Delhi. The WTP responses are internally valid: WTP increases with the size of the risk reduction, income, and exposure to road traffic risks, as measured by length of commute and whether the respondent drives a motorcycle. As a result, the value of a statistical life (VSL) varies across groups of beneficiaries. For the most highly-exposed individuals the VSL is about 150,000 Purchasing Power Parity (PPP) dollars.

The effect of the background risk in a simple chance improving decision model

We experimentally investigate the effect of an independent and exogenous background risk to initial wealth on subjects’ risk attitudes and explore an appropriate incentive mechanism when identical or similar tasks are repeated in an experiment. Taking a simple chance improving decision model under risk where the winning probabilities are negatively related to the potential gain, we find that such a background risk tends to make risk-averse subjects behave more risk aversely. Furthermore, we find that risk-averse subjects tend to show decreasing absolute risk aversion (DARA), and that a random round payoff mechanism (RRPM) would control the possible wealth effect. This suggests that RRPM would be a better incentive mechanism for an experiment where repetition of a task is used.

The sensitivity of subjective probability to time and elicitation method

The paper reports the results of a survey designed to elicit probability judgements for different types of events: ‘pure chance’ events, for which objective probabilities can be calculated; ‘public’ events, about which there may be some discussion in social groups and the media; and ‘personal’ events, such as those relating to crime or accidental injury. Even among respondents deemed to be ‘well-calibrated’ in the domain of pure chance events we find limited sensitivity to the ‘temporal scope’ of public and personal events—this being especially marked for personal events. We discuss possible reasons and some implications for policy-related survey work.

Environmental disasters as risk regulation catalysts? The role of Bhopal,Chernobyl, Exxon Valdez,Love Canal,and Three Mile Island in shaping U.S. environmental law

Unexpected events such as environmental catastrophes capture wide public attention. Soon after five major shocks—Three Mile Island, Love Canal, Bhopal, Chernobyl, and the Exxon Valdez oil spill—Congress voted on new risk regulation. This paper conducts an event study to test whether individual congressional representatives were “shocked” by these environmental disasters into increasing their probability of voting in favor of risk legislation. On average, representatives were less likely to vote in favor of bills tied to these five events. Significant heterogeneity in representatives’ responses to these shocks is documented. Liberal Northeast representatives were most likely to increase their pro-environment voting in the aftermath of these shocks.

Individual and group decision making under risk: An experimental study of Bayesian updating and violations of first-order stochastic dominance

This paper reports the results of experiments designed to test whether individuals and groups abide by monotonicity with respect to first-order stochastic dominance and Bayesian updating when making decisions under risk. The results indicate a significant number of violations of both principles. The violation rate when groups make decisions is substantially lower, and decreasing with group size, suggesting that social interaction improves the decision-making process. Greater transparency of the decision task reduces the violation rate, suggesting that these violations are due to judgment errors rather than the preference structure. In one treatment, however, less complex decisions result in a higher error rates.

Cancer premiums and latency effects: A risk tradeoff approach for valuing reductions in fatal cancer risks

Many studies estimate individuals’ values for avoiding fatality risks; however, most value-of-statistical-life studies focus on accident-related deaths. Consequently, little is known about preferences for avoiding other fatal risks, such as cancer. Cancer may engender strong feelings of dread, leading to a “cancer premium,” but cancer latency periods may have the opposite effect. Using a national survey, we elicit relative preferences for avoiding fatal cancer and auto-accident risks. We find strong preferences for avoiding cancer risks. With a 5-year latency, they are valued roughly three times greater than immediate accident risks, declining to 50% greater for a 25-year latency.

Individual decision-making experiments with risk and intertemporal choice

Many decisions require tradeoffs over time and in the presence of risk. To examine interactions between risk and intertemporal effects we developed a laboratory experiment. In the experiment, subjects choose between payoffs that take place at different points in time. We find that very few subjects are consistently risk averse or risk loving. Instead, we find that subjects are less patient in the presence of risk. We also find that increased risk decreases subjects’ patience levels. However, we do not find evidence that the effect of risk on the intertemporal decision depends on the length of the temporal delay.

Preferences and decision errors in the winner’s curse

The problem of asymmetric information causes a winner’s curse in many environments. Given many unsuccessful attempts to eliminate it, we hypothesize that some people ‘prefer’ the lotteries underlying the winner’s curse. Study 1 shows that after removing the hypothesized cause of error, asymmetric information, half the subjects still prefer winner’s curse lotteries, implying past efforts to de-bias the winner’s curse may have been more successful than previously recognized since subjects prefer these lotteries. Study 2 shows risk-seeking preferences only partially explain lottery preferences, while non-monetary sources of utility may explain the rest. Study 2 suggests lottery preferences are not independent of context, and offers methods to reduce the winner’s curse.

A tractable method to measure utility and loss aversion under prospect theory

This paper provides an efficient method to measure utility under prospect theory. Our method minimizes both the number of elicitations required to measure utility and the cognitive burden for subjects, being based on the elicitation of certainty equivalents for two-outcome prospects. We applied our method in an experiment and were able to replicate the main findings on prospect theory, suggesting that our method measures what it is intended to. Our data confirmed empirically that risk seeking and concave utility can coincide under prospect theory. Utility did not depend on the probability used in the elicitation, which offers support for the validity of prospect theory.

Valuing publicly sponsored research projects: Risks,scenario adjustments,and inattention

Survey-based choice scenarios used to value non-market public goods typically preclude any risk that the benefits described may not be delivered. Our survey specifies explicit risks of (a) outright program failure and (b) program redundancy due to possible private sector substitutes. Additionally, most analyses assume that survey subjects fully accept these scenarios and that all provided information receives their complete attention. Our discounted expected utility model of choice accommodates both these objective risks and the possibility of subjective scenario adjustment or selective inattention by respondents. We then counterfactually simulate willingness-to-pay in the absence of these distortions.

Conspicuous conservatism in risk choice

We analyze the risk levels chosen by agents who have private information regarding their quality, and whose performance will be judged and rewarded by outsiders. Assume that risk choice is observable. Agents will choose risk strategically to enhance their expected reputations. We show that conspicuous conservatism results: agents of different qualities choose levels below those that would be chosen if quality were observable. This happens because bad agents must cloak their identity by choosing the same risk level as good agents, and good agents are more likely to distinguish themselves if they reduce the risk level. Our results contrast starkly with those for the case when risk choice cannot be observed.

Correcting expected utility for comparisons between alternative outcomes: A unified parameterization of regret and disappointment

A unified parameterization of an expected utility model corrected for regret and disappointment effects is presented, constrained to conform to a well-known choice pattern, the common consequence effect, a special case of the Allais paradox. For choices subject to regret and disappointment effects to be consistent with this choice pattern, the function that corrects the utility of the obtained outcome has to have a positive second derivative for its regret component and a negative second derivative for its disappointment component. These hypothesized functional forms make predictions about the relative effect that small vs. large differences between obtained and alternative outcomes should have on people’s experiences of regret or disappointment.

Eliciting decision weights by adapting de Finetti’s betting-odds method to prospect theory

This paper extends de Finetti’s betting-odds method for assessing subjective beliefs to ambiguous events. Thus, a tractable manner for measuring decision weights under ambiguity is obtained. De Finetti’s method is so transparent that decision makers can evaluate the relevant tradeoffs in complex situations. The resulting data can easily be analyzed, using nonparametric techniques. Our extension is implemented in an experiment on predicting next-day’s performance of the Dow Jones and Nikkei stock indexes, where we test the existence and nature of rank dependence, finding usual patterns. We also find violations of rank dependence.

Whom should we believe? Aggregation of heterogeneous beliefs

We examine the collective risk attitude of a group with heterogeneous beliefs. We prove that the wealth-dependent probability distribution used by the representative agent is biased in favor of the beliefs of the more risk tolerant consumers. Moreover, increasing disagreement on the state probability raises the state probability of the representative agent. It implies that when most disagreements are concentrated in the tails of the distribution, the perceived collective risk is magnified. This can help to solve the equity premium puzzle. We show that the trade volume and the equity premium are positively correlated.