Showing papers in "Journal of Risk and Uncertainty in 2018"

Goals as Reference Points in Marathon Running: A Novel Test of Reference Dependence

Abstract: Theories of reference-dependent preferences, such as Prospect Theory, imply that outcomes that are just below or just above a reference point are evaluated in a qualitatively distinct fashion. In a large-scale eld study of marathon runners, we test whether goals act as reference points in shaping the valuation of outcomes. Consistent with the Prospect Theory value function, we nd that satisfaction as a function of relative performance (the dierence between a runner’s time goal and her nishing time) exhibits loss aversion and diminishing sensitivity in both predictions of and actual experienced satisfaction. However, in contrast to the standard accounts of reference dependence, we observe that loss aversion is partially driven by a discontinuity or jump at the reference point. In addition, loss aversion is moderated by goal importance, with higher goal importance producing more loss aversion. Finally, we nd that a runner’s time goal as well as their previous marathon times simultaneously impact runner satisfaction, providing support for the impact of multiple reference points on satisfaction.

Responsiveness to feedback as a personal trait

Abstract: We investigate individual heterogeneity in the tendency to under-respond to feedback (“conservatism”) and to respond more strongly to positive compared to negative feedback (“asymmetry”). We elicit beliefs about relative performance after repeated rounds of feedback across a series of cognitive tests. Relative to a Bayesian benchmark, we find that subjects update on average conservatively but not asymmetrically. We define individual measures of conservatism and asymmetry relative to the average subject, and show that these measures explain an important part of the variation in beliefs and competition entry decisions. Relative conservatism is correlated across tasks and predicts competition entry both independently of beliefs and by influencing beliefs, suggesting it can be considered a personal trait. Relative asymmetry is less stable across tasks, but predicts competition entry by increasing self-confidence. Ego-relevance of the task correlates with relative conservatism but not relative asymmetry.

Present bias and health

Abstract: This study uses a dynamic discrete choice model to examine the degree of present bias and naivete about present bias in individuals’ health care decisions. Clinical guidelines exist for several common chronic diseases. Although the empirical evidence for some guidelines is strong, many individuals with these diseases do not follow the guidelines. Using persons with diabetes as a case study, we find evidence of substantial present bias and naivete. Counterfactual simulations indicate the importance of present bias and naivete in explaining low adherence rates to health care guidelines.

Discounting health and money: New evidence using a more robust method

Abstract: This study compares discounting for money and health in a field study. We applied the direct method, which measures discounting independent of utility, in a representative French sample, interviewed at home by professional interviewers. We found more discounting for money than for health. The median discount rates (6.5% for money and 2.2% for health) were close to market interest rates, suggesting that at the aggregate level the direct method solves the puzzle of unrealistically high discount rates typically observed in applied economics. Constant discounting fitted the data better than the hyperbolic discounting models that we considered. The substantial individual heterogeneity in discounting was correlated with age and occupation.

Complexity in risk elicitation may affect the conclusions: A demonstration using gender differences

Abstract: The Holt and Laury (American Economic Review, 92(5), 1644–1655, 2002) mechanism (HL) is the most widely-used method for eliciting risk preferences in economics. Participants typically make ten decisions with different variance options, with one of these choices randomly chosen for actual payoff. For this mechanism to provide an accurate measure of risk aversion, participants need to understand the choices and give consistent responses. Unfortunately, inconsistent and even dominated choices are often made. Can these mistakes lead to a misrepresentation of economic phenomena? We use gender differences in risk taking to test this question. In contrast to many findings in the literature, HL results typically do not find significant gender differences. We compare the HL approach, where we replicate the lack of significant gender differences, with a simpler presentation of the same choices in which participants make only one of the ten HL decisions; this simpler presentation yields strong gender differences indicating that women are more risk averse than men. We also find gender differences in the consistency of decisions. We believe that the results found in the simpler case are more reflective of underlying preferences, since the task is considerably easier to understand. Our results suggest that the complexity and structure of the risk elicitation mechanism can affect measured risk preferences. The issue of complexity and comprehension is also likely to be present with elicitation mechanisms in other realms of economic preferences.

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

Abstract: 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.

Making the Anscombe-Aumann approach to ambiguity suitable for descriptive applications

Abstract: The Anscombe-Aumann (AA) model, originally introduced to give a normative basis to expected utility, is nowadays mostly used for another purpose: to analyze deviations from expected utility due to ambiguity (unknown probabilities). The AA model makes two ancillary assumptions that do not refer to ambiguity: expected utility for risk and backward induction. These assumptions, even if normatively appropriate, fail descriptively. This paper relaxes these ancillary assumptions to avoid the descriptive violations, while maintaining AA’s convenient mixture operation. Thus, it becomes possible to test and apply all AA-based ambiguity theories descriptively while avoiding confounds due to violated ancillary assumptions. The resulting tests use only simple stimuli, avoiding noise due to complexity. We demonstrate the latter in a simple experiment where we find that three assumptions about ambiguity, commonly made in AA theories, are violated: reference independence, universal ambiguity aversion, and weak certainty independence. The second, theoretical, part of the paper accommodates the violations found for the first ambiguity theory in the AA model—Schmeidler’s CEU theory—by introducing and axiomatizing a reference dependent generalization. That is, we extend the AA ambiguity model to prospect theory.

Temporal discounting of gains and losses of time: An experimental investigation

Abstract: This paper investigates “asymmetries” between non-monetary gains and losses in intertemporal choice. We considered gains and losses of spare/working time with respect to a reference duration defined in a working contract. Specifically, we elicited a behavioral model of intertemporal choice that accounts for a gain/loss-dependent discounting function and a reference-dependent utility. Additionally, we did not impose preference for the present (positive discounting) and allowed for both decreasing and increasing impatience. While our results are standard regarding the discount of money (our baseline treatment), our subjects heavily discounted gains of time. More patience was observed for losses of time and a sizable portion of subjects even exhibited negative discounting, i.e. they preferred to expedite losses of time. Our econometric estimations also reveal a much larger heterogeneity of behavior in terms of both utility and discounting for gains and losses of spare time as compared to money.

Valuing the risk of workplace sexual harassment

Abstract: Using data on sexual harassment charges filed with the Equal Employment Opportunity Commission, I calculate the risk of sexual harassment by gender, industry, and age and establish that white females, but not nonwhite females, receive a compensating wage differential for exposure to a higher risk of sexual harassment. I use this risk premium to calculate the value of statistical harassment (VSH) in a manner analogous to the calculation of the value of statistical life (VSL). The VSH is around $7.6 million, about three-quarters of the size of the most-commonly cited levels of the VSL, and far above the maximum damages award for sexual harassment available under federal law. Boosting the maximum damages award to equal the VSH would create the appropriate economic incentives for organizations to deter sexual harassment.

Age, autos, and the value of a statistical life

Abstract: The value of a statistical life (VSL) is used to assign a dollar value to the benefits of health and safety regulations. Many of those regulations disproportionately benefit older people, but most estimates of the VSL come from hedonic wage regressions with few older workers and no retirees. Using automobile purchase decisions, I estimate a VSL for individuals from the age of 18 up to the age of 85. Combining information on vehicle holdings and use, household attributes, used vehicle prices, crash test results, and yearly fatal accidents for each make, model, and vintage automobile, I calculate a separate willingness to pay for reduced mortality for different age groups. I find a significant inverted-U shape to the age-VSL function that ranges from $1.5 to $19.2 million (in 2009 dollars). The shape and magnitude of the vehicle-based age-VSL relationship corroborate labor market estimates and extend the age range of revealed preference evidence on the relationship between age and the VSL.

Social interaction effects: The impact of distributional preferences on risky choices

Abstract: This paper identifies convex distributional preferences as a possible cause for the empirical observation that agents belonging to the same group tend to behave similarly in risky environments. We first show theoretically that convex distributional preferences imply social interaction effects in risky choices in the sense that observing a peer choose a risky (safe) option increases the agent’s incentive to choose the risky (safe) option as well, even when lotteries are stochastically independent and the agent can only observe the lottery chosen by the peer but not the corresponding outcome. We then confirm our theoretical predictions experimentally.

Risk and risk aversion effects in contests with contingent payments

Abstract: Contests by their very nature involve risk, winning and losing are both possible, and the gain from winning can itself be uncertain. The participants in a contest use resources to increase their chance of winning. The main focus of this analysis is on the effects of risk aversion and risk in contests where only winners pay for resources used to compete. When payment is contingent on winning, the effect of risk aversion is in the opposite direction of what occurs when costs are paid by both winners and losers. A number of contests observed in the marketplace that exhibit this contingent payment property are discussed.

Boundedly rational expected utility theory

Abstract: We build a satisficing model of choice under risk which embeds Expected Utility Theory (EUT) into a boundedly rational deliberation process. The decision maker accumulates evidence for and against alternative options by repeatedly sampling from her underlying set of EU preferences until the evidence favouring one option satisfies her desired level of confidence. Despite its EUT core, the model produces patterns of behaviour that violate standard EUT axioms, while at the same time capturing systematic relationships between choice probabilities, response times and confidence judgments, which are beyond the scope of theories that do not take deliberation into account.

Defaults, normative anchors, and the occurrence of risky and cautious shifts

Abstract: Choice shifts occur when individuals advocate a risky (safe) decision when acting as part of a group even though they prefer a safe (risky) decision when acting as individuals. Even though research in psychology and economics has produced a mass of evidence on this puzzling phenomenon, there is no agreement about which mechanism produces choice shifts. In an experiment, we investigate the performance of two prominent mechanisms that have been proposed to explain the phenomenon; (i) rank-dependent utility and (ii) a desire to conform to the wishes of the majority. The evidence provides clear support for the conformity explanation.

Estimating representations of time preferences and models of probabilistic intertemporal choice on experimental data

Abstract: We here estimate a number of alternatives to discounted-utility theory, such as quasi-hyperbolic discounting, generalized hyperbolic discounting, and rank-dependent discounted utility with three different models of probabilistic choice. The data come from a controlled laboratory experiment designed to reveal individual time preferences in two rounds of 100 binary-choice problems. Rank-dependent discounted utility and its special case—the maximization of present discounted value—turn out to be the best-fitting theory (for about two-thirds of all subjects). For a great majority of subjects (72%), the representation of time preferences in Luce’s choice model provides the best fit.

Your money and your life: Risk attitudes over gains and losses

Abstract: Prospect theory is the most influential descriptive alternative to the orthodox model of rational choice under risk and uncertainty, in terms of empirical analyses of some of its principal parameters and as a consideration in behavioural public policy. Yet the most distinctive implication of the theory—a fourfold predicted pattern of risk attitudes called the reflection effect—has been infrequently studied and with mixed results over money outcomes, and has never been completely tested over health outcomes. This article reports tests of reflection over money and health outcomes defined by life years gained from treatment. With open valuation exercises, the results suggest qualified support for the reflection effect over money outcomes and strong support over health outcomes. However, in pairwise choice questions, reflection was substantially ameliorated over life years, remaining significant only for treatments that offered short additional durations of life.

Corporate apology for environmental damage

Abstract: Apologies are a powerful way to restore trust and reduce punishment costs in bilateral settings. But what do we know about public apologies for large scale man-made disasters? Herein we report on results from an experiment with apologies in a multilateral setting: a firm-caused environmental disaster. Subjects read about an oil spill scenario, and learned whether the oil firm made a full apology, a partial apology, or no apology, and whether the firm had a good, bad, or no environmental reputation. A partial apology is one that fails to accept full material responsibility for damages, such as by shifting the blame to another party. We find that full apologies and better reputation reduce the demand for punishment. However, full apologies and reputation are substitutes, with reputation being significantly more important. Additionally, apologies do not reduce the demand for compensation and may increase it if the firm is clearly a bad actor, or if admission of guilt is the only information subjects have. Our results help explain corporate social responsibility investments and greenwashing, and why many public apologies over an environmental disaster are only partial apologies.

Dinner with Bayes: On the revision of risk beliefs

Abstract: We study how people form and revise health risk beliefs based on food safety information. In an online experiment, subjects stated their perceived risk of contracting a foodborne illness before and after receiving information about the population average risk and the eating habits of the average consumer. Precautionary effort in handling and preparing food reduced prior risk beliefs, but did not affect the belief revision process. About one quarter of subjects either fully ignored the information provided or revised their beliefs inconsistently with the Bayesian learning hypothesis. We find several factors related to the subjects’ numerical skills that explain information refusal and inconsistent belief revisions and discuss them in the context of health risks.

Reporting probabilistic expectations with dynamic uncertainty about possible distributions

Abstract: We study how experimental subjects report subjective probability distributions in the presence of ambiguity characterized by uncertainty over a fixed set of possible probability distributions generating future outcomes. Subjects observe draws from the true but unknown probability distribution generating outcomes at the beginning of each period of the experiment and state at selected periods a) the likelihoods that each probability distribution in the set is the true distribution, and b) the likelihoods of future outcomes. We estimate heterogeneity of rules used to update uncertainty about the true distribution and rules used to report distributions of future outcomes. We find that approximately 65% of subjects report distributions by properly weighing the possible distributions using their expressed uncertainty over them, while 22% of subjects report distributions close to the distribution they perceive as most likely. We find significant heterogeneity in how subjects update their expressed uncertainty. On average, subjects tend to overweigh the importance of their prior uncertainty relative to new information, leading to ambiguity that is substantially more persistent than would be predicted using Bayes’ rule. Counterfactual simulations suggest that this persistence will likely hold in settings not covered by our experiment.

Evidence for multiple strategies in choice under risk

Abstract: 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.

Spatial externalities and risk in interdependent security games

Abstract: Individuals regularly invest in self-protection to reduce the risk of an adverse event. The effectiveness of self-protection often depends on the actions of other economic agents and can be modeled as a stochastic coordination game with multiple Pareto-ranked equilibria. We use lab experiments to analyze tacit coordination in stochastic games with two kinds of interdependencies in payoffs: “non-spatial” in which every agent’s action has an impact on the risk faced by every other agent, and “spatial” in which agents only impact the risk faced by their immediate neighbors. We also compare behavior in the stochastic games to deterministic versions of the same games. We find that coordination on the payoff-dominant equilibrium is significantly easier in the deterministic games than in the stochastic games and that spatial interdependencies lead to greater levels of coordination in the deterministic game but not in the stochastic game. The difficulty with coordination observed in the stochastic games has important implications for many real-world examples of interdependent security and also illustrates the importance of not relying on data from deterministic experiments to analyze behavior in settings with risk.

Decision irrationalities involving deadly risks

Abstract: This article provides an experimental analysis of two-armed bandit problems that have a different structure in which the first unsuccessful outcome leads to termination of the game. It differs from a conventional two-armed bandit problem in that there is no opportunity to alter behavior after an unsuccessful outcome. Introducing the risk of death into a sequential decision problem alters the structure of the problem. Even though play ends after an unsuccessful outcome, Bayesian learning after successful outcomes has a potential function in this class of two-armed bandit problems. Increasing uncertainty boosts the chance of long-term survival since ambiguous probabilities of survival are increased more after each successful outcome. In the independent choice experiments, a slim majority of participants displayed a preference for greater risk ambiguity. Particularly in the interdependent choice experiments, participants were overly deterred by ambiguity. For both independent and interdependent choices, there were several dimensions on which participants displayed within session rationality. However, participants failed to learn and improve their strategy over a series of rounds, which is consistent with evidence of bounded rationality in other challenging games.

Subjective beliefs and confidence when facts are forgotten

Abstract: Forgetting can be a salient source of uncertainty for subjective beliefs, confidence, and ambiguity attitudes. To investigate this, we run several experiments where people bet on propositions (facts) that they cannot recall with certainty. We use betting preferences to infer subjects’ revealed beliefs and their revealed confidence in these beliefs. Forgetting is induced via interference tasks and time delays (up to one year). We observe a natural memory decay pattern where beliefs become less accurate and confidence is reduced as well. Moreover, we find a form of comparative ignorance where subjects are more ambiguity averse when they cannot recall the truth rather than never having learnt it. In a different vein, we identify an overconfidence pattern: on average, subjects overpay for bets on propositions that they believe in, but underpay for the opposite bets. We formulate a two-signal behavioral model of forgetting that generates all of these patterns. It suggests new testable hypotheses that are confirmed by our data.