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.     

Dynamic Choice, Independence and Emotions

From the viewpoint of the independence axiom of expected utility theory, an interesting empirical dynamic choice problem involves the presence of a “global risk,” that is, a chance of losing everything whichever safe or risky option is chosen. In this experimental study, participants have to allocate real money between a safe and a risky project. Treatment variable is the particular decision stage at which a global risk is resolved: (i) before the investment decision; (ii) after the investment decision, but before the resolution of the decision risk; (iii) after the resolution of the decision risk. The baseline treatment is without global risk. Our goal is to investigate the isolation effect and the principle of timing independence under the different timing options of the global risk. In addition, we examine the role played by anticipated and experienced emotions in the choice problem. Main findings are a violation of the isolation effect, and support for the principle of timing independence. Although behavior across the different global risk cases shows similarities, we observe clear differences in people’s affective responses. This may be responsible for the conflicting results observed in earlier experiments. Dependent on the timing of the global risk different combinations of anticipated and experienced emotions influence decision making.      

Social comparison and risk taking behavior

This paper studies the effects of social comparison on risk taking behavior. In our theoretical framework, decision makers evaluate the consequences of their choices relative to both their own and their peers’ conditions. We test experimentally whether the position in the social ranking affects risk attitudes. Subjects interact in a simulated workplace environment where they perform a work task, receive possibly different wages, and then undertake a risky decision that may produce an extra gain. We find that social comparison matters for risk attitudes. Subjects are more risk averse in the presence of small social gain than social loss. In addition, risk aversion is decreasing in the size of the social gain.     

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.     

Individual and couple decision behavior under risk: evidence on the dynamics of power balance

This article reports results of an experiment designed to analyze the link between risky decisions made by couples and risky decisions made separately by each spouse. We estimate both the spouses and the couples’ degrees of risk aversion, we assess how the risk preferences of the two spouses aggregate when they make risky decisions, and we shed light on the dynamics of the decision process that takes place when couples make risky decisions. We find that, far from being fixed, the balance of power within the household is malleable. In most couples, men have, initially, more decision-making power than women but women who ultimately implement the joint decisions gain more and more power over the course of decision making.     

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.

     

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.     

Heterogeneity in life-duration preferences: Are risky recreationists really more risk loving?

We conduct multiple price list experiments that elicit life duration risk preferences from amateur auto racers, technical rock climbers, SCUBA divers, and a student control group. We posit a preference function that allows for risk aversion and probability weighting. We are particularly interested in whether the behavior of risk takers, such as risky recreationists or smokers, is best explained by a risk-tolerant utility function or if immunity to possibility bias arising from overweighting of low probabilities is a more important motivator of the choice to engage in risky activities. We find that amateur auto racers are more rational than either students or other risky recreationists because they are less likely to overemphasize low-probability events. Women, older subjects, and rock climbers are more susceptible to possibility bias than others, making them likely to overinvest in disease treatments that have a low probability of success.     

Comparing behavior under risk and under ambiguity in a lifecycle experiment

Experiments on intertemporal consumption typically show that people have difficulties in optimally solving such problems. Previous studies have focused on contexts in which agents are faced with risky future incomes and have to plan over long horizons. We present an experiment comparing decision making under certainty, risk, and ambiguity, over a shorter lifecycle. Results show that behavior in the ambiguity treatment is markedly different than in the risk condition and it is characterized by a significant pattern of under-consumption.     

Optimal insurance without expected utility: The dual theory and the linearity of insurance contracts

Models of the insurance markets and institutions are routinely based on expected utility. Since EU is being challenged by an increasing number of decision models, we examine whether EU-based models are robust in their predictions. To do so, we rework some basic models of optimal insurance contracts and equilibrium using the “dual” theory to EU of Yaari. When there is a single, insurable source of risk, dual theory permits only corner solutions if the contract itself is linear. This contrasts sharply with EU. Nonlinearity, and thereby the possibility of interior solutions, is introduced in two ways. First, the contract itself is nonlinear, i.e., a deductible insurance policy. Or second, the decision maker is subject to some background risk such as uninsurable risky assets or default of the insurer. When decision problems are subject to nonlinearity, the predictions on optimal insurance are more similar to, though not identical with, those generated with EU.     

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.     

Perceived Hazard and Product Choice: An Application to Recreational Site Choice

We develop a "perceived hazard" model that estimates consumers' endogenous risk perceptions about products. These perceptions are then linked to a model of product choice. Our approach thus departs from the expected utility model that depends upon external risk assessments. In an application to recreational fishing, we find that anglers' perceived hazards associated with fish consumption advisories do affect product (recreational site) choice. Anglers' perceptions also affect welfare measures because the benefits of contaminant removal flow from these perceptions. The perceived hazard/product choice model is applicable to a wide variety of risky choices consumers face.     

Sampling experience reverses preferences for ambiguity

People often need to choose between alternatives with known probabilities (risk) and alternatives with unknown probabilities (ambiguity). Such decisions are characterized by attitudes towards ambiguity, which are distinct from risk attitudes. Most studies of ambiguity attitudes have focused on the static case of single choice, where decision makers typically prefer risky over ambiguous prospects. However, in many situations, decision makers may be able to sample outcomes of an ambiguous alternative, allowing for inferences about its probabilities. The current paper finds that such sampling experience reverses the pattern of ambiguity attitude observed in the static case. This effect can only partly be explained by the updating of probabilistic beliefs, suggesting a direct effect of sampling on attitudes toward ambiguity.     

The economics of adding and subdividing independent risks: Some comparative statics results

In this paper we address the problem of determining whether adding independent risks or subdividing them is a good substitute for insurance. Despite the fact that accepting more i.i.d. risks increases total risk, it is shown that some risk-averse decision makers can rationally reduce their demand for insurance by doing so. Similarly, a better diversified portfolio of i.i.d. risky assets can rationally be more insured, even if diversification is a risk-reduction scheme. We derive conditions sufficient to obtain unambiguous comparative statics results. Assuming that absolute risk aversion is decreasing and that the fourth derivative of the utility function is positive, we show that diversification is an exceptionally good substitute for insurance. Under the same conditions, adding independent risks to wealth reduces the demand for insurance on each unit.     

Mean-risk decision analysis

Some decision theorists criticize expected utility decision analysis and propose mean-risk decision analysis as a replacement. They claim that expected utility decision analysis neglects attitudes toward risk whereas mean-risk decision analysis accords these attitudes their proper status. However mean-risk decision analysis and expected utility decision analysis are not incompatible, and it is advantageous for decision theory to develop each in a way that complements the other. Here I present a mean-risk rule that governs preferences among options and options given states. This mean-risk rule complements an expected utility rule that takes the utility of an option-state pair as the utility of the option given the state. I argue for the mean-risk rule using principles concerning basic intrinsic desires. The rule is comparative, but the last section offers some suggestions for its quantitative development.I am grateful for comments from my colleague, Henry E. Kyburg, Jr.     

From fun to fraught: marketing to kids and regulating “risky foods” in Canada

ABSTRACT

In an era of industrialized food production, ultra-processed foods, “Big Food” marketing, and growing obesity rates, food has come to be framed as an object of risk – and as an object of regulation. Such reframing has fascinating implications related to issues of responsibility and decision making, especially when it comes to children’s food. This article probes the relationship between representation, regulation and “risky” consumption with respect to children’s food. I examine how child-targeted foods become framed as “risky” and what counts as “risky” food messaging under Health Canada’s commitment to restrict the marketing of unhealthy foods to children. Detailing the tension between food as a risk object and food as a child object, I suggest how issues of semantic provisioning and the politics of the unseen work to complicate and destabilize the (seemingly) straightforward process of prohibiting unhealthy food marketing to children.     

Mean-preserving changes in risk with tail-dominance

In this paper, we consider a class of mean preserving increases in risk such that all risk-averse decision makers respond to an increase in risk by reducing the level of their risky activities. The type of increase in risk that we consider is based on the notion of tail dominance which generalizes other cases previously discussed in the literature.L. Eeckhoudt is Professor of Economics at the Catholic Faculties of Mons (Belgium) and Lille (France). P. Hansen is Professor of Operations Research at Ecole des Hautes Etudes Commerciales, Montréal. Both authors have benefited from comments by P. Caperaa, G. Dionne, J. Meyer and H. Varian. They also thank A. Coopman who carefully reviewed and improved the English style.     

The two faces of independence: betweenness and homotheticity

This paper shows that expected utility belongs to the intersection of models satisfying betweenness and a homotheticity condition for risky choice. Betweenness models can accommodate variable risk attitudes, originally highlighted by the Allais paradox, by restricting indifference curves to be linear while allowing non-parallelism. Homotheticity, in contrast, restricts indifference curves to be parallel while permitting non-linearities, such as those highlighted by inverse-S probability weighting. Data from an experiment indicate that approximately 2/3s of participants satisfied homotheticity. Of this group, about half satisfied the expected utility hypothesis. The other half violated expected utility and therefore betweenness. These results indicate that homothetic preferences, and in particular those violating betweenness, can be empirically relevant for decision making under risk.

     

Stochastic dominance in multicriterion analysis under risk

Traditionally, in the literature on the modelling of decision aids one notes the propensity to treat expected utility models and outranking relation models as rivals. It may be possible, however, to benefit from the use of both approaches in a risky decision context. Stochastic dominance conditions can be used to establish, for each criterion, the preferences of a decision maker and to characterise them by a concave or convex utility function.Two levels of complexity in preference elicitation, designated as clear and unclear, are distinguished. Only in the case of unclear preferences is it potentially interesting to attempt to estimate the value function of the decision maker, thus obtaining his (her) preferences with a reduced number of questions. The number of questions that must be asked of the decision maker depends upon the level of the concordance threshold that he(she) requires in the construction of the outranking relations using the ELECTRE method.