Risk aversion under preference uncertainty

We show that if an agent is uncertain about the precise form of his utility function, his actual relative risk aversion may depend on wealth even if he knows his utility function lies in the class of constant relative risk aversion (CRRA) utility functions. We illustrate the consequences of this result for asset allocation: poor agents that are uncertain about their risk aversion parameter invest less in risky assets than wealthy investors with identical risk aversion uncertainty. Keywords: Risk Aversion , Preference Uncertainty , Risk-taking , Asset Allocation JEL Classification: D81, D84, G11 This Version: November 25, 201

DARA and DRRA option bounds from concurrently expiring options

In this paper we derive option bounds from concurrently expiring options assuming the representative investor has decreasing absolute {relative} risk aversion. We show that given the prices of the underlying stock and n concurrently expiring options, the DARA {DRRA} option bound is given by a representative investor who has piecewise constant absolute {relative} risk aversion. We also derive option bounds from concurrently expiring option prices assuming the representative investor has decreasing and bounded absolute {relative} risk aversion

THEORY AND MISBEHAVIOR OF FIRST-PRICE AUCTIONS: THE IMPORTANCE OF INFORMATION FEEDBACK IN EXPERIMENTAL MARKETS

This article reports the results of a market experiment designed to test the predictions of the constant relative risk aversion model and to study the importance of information feedback in repeated first-price sealed-bid auctions. The data reveal that introduction of price information feedback implies a significant change of individual behavior. Without price information feedback, the data support the risk neutral Nash equilibrium prediction; with price information feedback, on the other hand, subjects overbid the risk neutral Nash equilibrium significantly. The constant relative risk aversion model is rejected since it predicts overbidding for both feedback conditions.Experimental Economics, First-price Sealed-bid Auctions, Independent Private Value Model, Bidding Theory, Risk Aversion

Agricultural Risk Aversion Revisited: A Multicriteria Decision-Making Approach

In modelling farm systems it is widely accepted that risk plays a central role. Furthermore, farmers' risk aversion determines their decisions in both the short and the long run. This paper presents a methodology based on multiple criteria mathematical programming to obtain relative and absolute risk aversion coefficients. We rely on multiattribute utility theory (MAUT) to elicit a separable additive multiattribute utility function and then estimate the risk aversion coefficients and apply this methodology to an irrigated area of Northern Spain. The results show a wide variety of attitudes to risk among farmers, who mainly exhibit decreasing absolute risk aversion (DARA) and constant relative risk aversion (CRRA).Risk analysis, Agriculture, Utility theory, Multiple criteria analysis, Risk and Uncertainty,

A Simple Proof That Futures Markets are Almost Always Informationally Inefficient

Previous work which showed that prices could aggregate perfectly the diverse information of traders depended critically on the assumption that all agents had constant absolute risk utility. We show that either all agents must have constant absolute risk aversion utility, or all must have constant relative aversion in order for the strong form of the efficient market hypothesis to hold generically.

Who participates in tax amnesties? Self-selection of risk-averse taxpayers

In this paper we model taxpayer participation in an unanticipated tax amnesty which can be entered by paying a fixed amount. Taxpayers are characterized by a Constant Relative Risk Aversion (CRRA) utility function and differ in relative risk aversion coefficient and in income. With minor changes the same model also describes a FATOTA (Fixed Amount of Taxes or Tax Audit) system. Our results show that amnesties may fail as a self-selective device to fully separate large-scale from small-scale tax evaders and to extract resources from the former. Only taxpayers whose relative risk aversion falls within a given interval participate, while those whose evasion is too small or too large do not enter. The model is used to estimate relative risk aversion and tax evasion of participants in the 1991 and 1994 Italian income tax amnesties.tax amnesty, tax evasion, relative risk aversion, self-selection

Relative Risk Aversion Is Constant: Evidence from Panel Data

Most classical tests of constant relative risk aversion (CRRA) based on individual portfolio composition use cross sectional data. Such tests must assume that the distributions of wealth and preferences are independent. We use panel data to analyze how individuals’ portfolio allocation between risky and riskless assets varies in response to changes in total financial wealth. We find the elasticity of the risky asset share to wealth to be small and statistically insignificant, supporting the CRRA assumption; this finding is robust when the sample is restricted to households experiencing ‘large’ income variations. Various extensions are discussed.-

Measuring Risk Aversion and the Wealth Effect

Measuring risk aversion is sensitive to assumptions about the wealth in subjects’ utility functions. Data from the same subjects in low- and high-stake lottery decisions allow estimating the wealth in a pre-specified one-parameter utility function simultaneously with risk aversion. This paper first shows how wealth estimates can be identified assuming constant relative risk aversion (CRRA). Using the data from a recent experiment by Holt and Laury (2002), it is shown that most subjects’ behavior is consistent with CRRA at some wealth level. However, for realistic wealth levels most subjects’ behavior implies a decreasing relative risk aversion. An alternative explanation is that subjects do not fully integrate their wealth with income from the experiment. Within-subject data do not allow discriminating between the two hypotheses. Using between-subject data, maximum-likelihood estimates of a hybrid utility function indicate that aggregate behavior can be described by expected utility from income rather than expected utility from final wealth and partial relative risk aversion is increasing in the scale of payoffs

Precautionary Saving and Consumption Smoothing Across Time and Possibilities

This paper examines how aversion to risk and aversion to intertemporal substitution determine the strength of the precautionary saving motive in a two-period model with Selden/Kreps-Porteus preferences. For small risks, we derive a measure of the strength of the precautionary saving motive which generalizes the concept of "prudence" introduced by Kimball (1990b). For large risks, we show that decreasing absolute risk aversion guarantees that the precautionary saving motive is stronger than risk aversion, regardless of the elasticity of intertemporal substitution. Holding risk preferences fixed, the extent to which the precautionary saving motive is stronger than risk aversion increases with the elasticity of intertemporal substitution. We derive sufficient conditions for a change in risk preferences alone to increase the strength of the precautionary saving motive and for the strength of the precautionary saving motive to decline with wealth. Within the class of constant elasticity of intertemporal substitution, constant-relative risk aversion utility functions, these conditions are also necessary.

Measuring risk attitudes among Mozambican farmers:

Although farmers in developing countries are generally thought to be risk averse, little is known about the actual form of their risk preferences. In this paper, we use a relatively large field experiment to explore risk preferences related to sweet potato production among a sample of farmers in northern Mozambique. We explicitly test whether preferences follow the constant relative risk aversion (CRRA) utility function and whether farmers follow expected utility theory or rank dependent utility theory in generating their preferences. We find that we can reject the null that farmers'preferences follow the CRRA utility function in favor of the more flexible power risk aversion preferences. In a mixture model, we find that about three-fourths of farmers in our sample develop risk preferences by rank dependent utility. We also find that by making the common CRRA assumption in our sample, we poorly predict risk preferences among those who are less risk averse.Sweet potato, Risk preferences, constant relative risk aversion (CRRA), farmers preferences,