Production and insurance under regret aversion

This paper examines the behavior of a regret-averse producer facing revenue risk. To insure against the revenue risk, the producer can purchase a coinsurance contract with an endogenously chosen coinsurance rate. Regret-averse preferences are characterized by a utility function that includes disutility from having chosen ex-post suboptimal alternatives. We show that the regret-averse producer never fully insures against the revenue risk even though the coinsurance contract is actuarially fair. When the producer is sufficiently regret averse and the loss probability is high, we further show that the regret-averse producer chooses not to purchase the actuarially fair coinsurance contract. Even when purchasing the actuarially fair coinsurance contract is optimal, we derive sufficient conditions under which the regret-averse producer reduces the optimal output level as compared to that without the coinsurance contract. These results are distinct from those under pure risk aversion, thereby making the consideration of regret aversion crucial.     

Production and hedging decisions under regret aversion

In this paper, we investigate regret-averse firms' production and hedging behaviors. We first show that the separation theorem is still alive under regret aversion by proving that regret aversion is independent of the level of optimal production. On the other hand, we find that the full-hedging theorem does not always hold under regret aversion as the regret-averse firms take hedged positions different from those of risk-averse firms in some situations. With more regret aversion, regret-averse firms will hold smaller optimal hedging positions in an unbiased futures market. Furthermore, contrary to the conventional expectations, we show that banning firms from forward trading affects their production level in both directions.     

Minimax regret and strategic uncertainty

This paper introduces a new solution concept, a minimax regret equilibrium, which allows for the possibility that players are uncertain about the rationality and conjectures of their opponents. We provide several applications of our concept. In particular, we consider price-setting environments and show that optimal pricing policy follows a non-degenerate distribution. The induced price dispersion is consistent with experimental and empirical observations (Baye and Morgan (2004) [4]).     

Fixed versus variable rate loans under regret aversion

This paper examines the optimal mix of fixed and variable rate loans of a competitive bank facing funding cost uncertainty, where the bank is not only risk averse but also regret averse. Regret aversion is characterized by a utility function that includes disutility from having chosen ex-post suboptimal alternatives. We show that a negative spread between fixed and variable rate loans is a necessary but not sufficient condition for the dominance of variable rate loans over fixed rate loans. If the bank optimally extends both fixed and variable rate loans, the total amount of loans depends neither on the bank's regret aversion nor on the funding cost uncertainty. The bank, however, optimally lends less should it be forced to assume the entire funding cost uncertainty by exclusively extending fixed rate loans. Finally, using a two-state example, we show that the bank optimally extends more (less) fixed rate loans than in the case of pure risk aversion if the high (low) marginal cost of funds is more likely to prevail. Regret aversion as such plays a crucial role in determining the bank's optimal choice between fixed and variable rate loans.     

Stochastically independent randomization and uncertainty aversion

Summary.   This paper proposes a preference-based condition for stochastic independence of a randomizing device in a product state space. This condition is applied to investigate some classes of preferences that allow for both independent randomization and uncertainty or ambiguity aversion (a la Ellsberg). For example, when imposed on Choquet Expected Utility (CEU) preferences in a Savage framework displaying uncertainty aversion in the spirit of Schmeidler [27], it results in a collapse to Expected Utility (EU). This shows that CEU preferences that are uncertainty averse in the sense of Schmeidler should not be used in settings where independent randomization is to be allowed. In contrast, Maxmin EU with multiple priors preferences continue to allow for a very wide variety of uncertainty averse preferences when stochastic independence is imposed. Additionally, these points are used to reexamine some recent arguments against preference for randomization with uncertainty averse preferences. In particular, these arguments are shown to rely on preferences that do not treat randomization as a stochastically independent event. Received: February 10, 2000; revised version: March 30, 2000     

Past experience of uncertainty affects risk aversion

In an experiment with more than 500 participants we study how past experience of uncertainty (imperfect knowledge of the state space) affects risk preferences. Participants in our experiment choose between a sure outcome and a lottery in 32 periods. All treatments are exactly identical in periods 17–32 but differ in periods 1–16. In the early periods of the risk treatment there is perfect information about the lottery; in the ambiguity Treatment participants perfectly know the outcome space but not the associated probabilities; in the unawareness treatment participants have imperfect knowledge about both outcomes and probabilities. We observe strong treatment effects on behavior in periods 17–32. In particular, participants who have been exposed to an environment with very imperfect knowledge of the state space subsequently choose lotteries with high (low) variance less (more) often compared to other participants. Estimating individual risk attitudes from choices in periods 17–32 we find that the distribution of risk attitude parameters across our treatments can be ranked in terms of first order stochastic dominance. Our results show how exposure to environments with different degrees of uncertainty can affect individuals’ subsequent risk-taking behavior.     

Mean-dispersion preferences and constant absolute uncertainty aversion

We axiomatize, in an Anscombe–Aumann framework, the class of preferences that admit a representation of the form V(f)=μ−ρ(d)$V(f)=\mu -\rho (d)$, where μ is the mean utility of the act f with respect to a given probability, d   is the vector of state-by-state utility deviations from the mean, and ρ(d)$\rho (d)$ is a measure of (aversion to) dispersion that corresponds to an uncertainty premium. The key feature of these mean-dispersion   preferences is that they exhibit constant absolute uncertainty aversion. This class includes many well-known models of preferences from the literature on ambiguity. We show what properties of the dispersion function ρ(⋅)$\rho (\cdot )$ correspond to known models, to probabilistic sophistication, and to some new notions of uncertainty aversion.     

Information,endogenous uncertainty and risk aversion

The importance of incomplete information and risk aversion for the allocation of economic resources is shown to depend critically on whether uncertainty is exogenously imposed or endogenously related to the ability of the price system to aggregate and disseminate the information possessed by the agents in a decentralized market economy. The specific example analysed in this paper is a two-period exchange model with competitive markets and a homogeneous product.Comments and suggestions by anonymous referees, Jacques Drèze, Jan Rose Sørensen, and financial support from the Danish Social Science Research Council are gratefully acknowledged.     

Ambiguity,uncertainty aversion and equilibrium welfare

Summary. In order to analyse the effect of ambiguity and uncertainty aversion on equilibrium welfare, a two period, pure exchange one good economy is considered. Agents are Choquet-expected-utility maximizers with same convex capacity and strictly concave utility index. It is proven that equilibrium is indeterminate whenever several probabilities in the core of the capacity minimize the expected value of aggregate endowment and not all agents have same expected endowments under those probabilities. It is further shown that small changes in aggregate endowment may have drastic welfare implications. A more general model is considered in the case of no aggregate uncertainty: agents have a set of priors and are uncertainty averse as modelled by Gilboa-Schmeidler [1989]. In the case of complete markets, it is shown that assets have a spread of equilibrium prices similar to the spread of no-arbitrage prices compatible with absence of arbitrage in markets with imperfections.Received: 2 June 2000, Revised: 27 March 2003, JEL Classification Numbers: D46, D59,D60, G12.I have benefited from conversations with L. Epstein, F. Magnien and J. M. Tallon.     

Status quo bias,multiple priors and uncertainty aversion

Motivated by the extensive evidence about the relevance of status quo bias both in experiments and in real markets, we study this phenomenon from a decision-theoretic prospective, focusing on the case of preferences under uncertainty. We develop an axiomatic framework that takes as a primitive the preferences of an agent for each possible status quo option, and provide a characterization according to which the agent considers a full-dimensional set of possible priors and abandons her status quo option only if she finds an alternative that returns a higher expected utility for each of these priors. We then show that, in this framework, the very presence of a status quo induces the agent to be more uncertainty averse than she would be without a status quo option.     

The role of risk aversion in public goods dilemmas with environmental uncertainty: an experimental analysis

The purpose of this study is to extend earlier research on environmental uncertainty in public goods dilemmas. The present paper reports the results of an experiment designed to examine the effect of risk aversion on public goods provision. A von Neumann–Morgenstern utility function with constant coefficient of relative risk aversion is used to investigate the impact of risk attitudes within a threshold public goods environment. The outcome of the threshold public goods experiment shows that subjects are indifferent to the changes in environmental conditions. Additionally, the analysis indicates that risk aversion is a significant determinant of voluntary public goods contribution level.     

Nonlinearity as an explanation of the forward exchange rate anomaly

This article shows that nonlinearity can provide an explanation for the forward exchange rate anomaly (Fama, 1984 Fama, E. 1984. Forward and spot exchange rates. Journal of Monetary Economics, 14: 319–38. [Crossref], [Web of Science ®] , [Google Scholar]). Using sterling-Canadian dollar data and modelling nonlinearity of unspecified form by means of a random field, we find strong evidence of time-wise nonlinearity and, significantly, obtain parameter estimates that conform with theory to a high degree of precision.     

Why uncertainty matters: discounting under intertemporal risk aversion and ambiguity

Uncertainty has an almost negligible impact on project value in the standard economic model. I show that a comprehensive evaluation of uncertainty and uncertainty attitude changes this picture fundamentally. The illustration of this result relies on the discount rate, which is the crucial determinant in balancing immediate costs against future benefits, and the single most important determinant of optimal mitigation policies in the integrated assessment of climate change. First, the paper removes an implicit assumption of (intertemporal or intrinsic) risk neutrality from the standard economic model. Second, the paper introduces aversion to non-risk uncertainty (ambiguity). I show a close formal similarity between the model of intertemporal risk aversion, which is a reformulation of the widespread Epstein–Zin–Weil model, and a recent model of smooth ambiguity aversion. I merge the models, achieving a threefold disentanglement between risk aversion, ambiguity aversion, and the propensity to smooth consumption over time.     

Adverse selection as an explanation of credit rationing and different lender types

An adverse selection model is utilized to demonstrate that informational asymmetry may make it wealth optimal for the financial intermediary (FI) to credit ration and to rationalize the existence of different lenders in the credit market. The crucial assumption is that borrowers differ in their tolerance for a lender-imposed default penalty, the severity of which also varies with the lender. The credit rationing portion proves that the FI will: 1) be forced by a binding regulatory constraint to overinvest in capital; 2) ration its worst risk class borrowers; 3) establish its optimal loan interest rate on the basis of the average quality of its loans and the interest rate elasticity of the borrower demand in its best risk category; and 4) decrease the total loan volume and increase the loan interest rate due to an increase in the capital requirement, but the effect on the default risk quality of its loan portfolio is ambiguous. The existence result is that if a lender has a high default penalty, he can charge a lower rate and attract only “good” borrowers, i.e., heterogeneous lender types encourage the screening of borrowers and vice versa.     

Misery loves company: Social regret and social interaction effects in choices under risk and uncertainty

Extensive field evidence shows individuals? decisions in settings involving uncertainty depend on their peers? decisions. One hypothesized cause of peer group effects is social interaction effects: an individual?s utility from an action is enhanced by others taking the same action. We employ a series of controlled laboratory experiments to study the causes of peer effects in choice under uncertainty. We find strong peer group effects in the laboratory. Our design allows us to rule out social learning, social norms, group affiliation, and complementarities as possible causes for the observed peer group effects, leaving social interaction effects as the likely cause. We use a combination of theory and empirical analysis to show that preferences including “social regret” are more consistent with the data than preferences including a taste for conformity. We observe spillover effects, as observing another?s choice of one risky gamble makes all risky gambles more likely to be chosen.     

An investigation into sexual orientation discrimination as an explanation for wage differences

This study explores the effects of sexual orientation on earnings. It is found that, ceteris paribus, men living with male partners tend to earn less than other men, and women living with female partners tend to earn more than other women. These earnings differentials tend to vary by region. They also vary by education and occupation for men, and with the presence of minor children for women. In addition, the age-earnings profiles of women living with female partners tend to be higher, flatter, and less concave than those of other women.     

Endogenous factor market distortion, risk aversion, and international trade under input uncertainty

In the context of non-diversifiable and sector-specific risks in labour markets, we show that the resulting factor market distortion – attributable to an endogenous intersectoral wage differential – can provide a possible rationale that explains why larger wage dispersion prevails in developing nations. We also demonstrate how endogenous wage distortions spill over to capital markets, with capital-poor economies offering lower rates of returns. In addition, we show that inequality in the distribution of wealth further deviates factor allocation away from first-best and impairs intersectoral mobility of the poor.
Ce mémoire montre que la distorsion dans le marché des facteurs qui résulte de risques non diversifiables et spécifiques à certains secteurs (et qui se traduit par un différentiel de salaire endogène entre secteurs) peut expliquer pourquoi on observe une dispersion plus grande des salaires dans les pays en voie de développement.On montre aussi comment des distorsions endogènes de salaires débordent vers les marchés de capitaux,ce qui fait que les pays pauvres en capital ont des rendements plus faibles.De plus, on montre que l'inégalité dans la distribution de la richesse contribue à faire dévier l'allocation des ressources de son optimum de premier ordre et nuit à la mobilité inter-sectorielle des pauvres.