Status,Risk-Taking and Intertemporal Substitution in an Endogenous Growth Model

This paper examines intertemporal risk-taking in a stochastically growing economy with externalities in human capital accumulation where agents have preferences for social status. In order to isolate the effects of status concerns on long-run expected growth, the analysis is embedded in a non-expected utility setting, which disentangles the effects from risk aversion and intertemporal substitution. We examine the interaction between status desire and risk, risk aversion and intertemporal substitution. The externalities generated by the status game are able to correct the allocative distortions from the knowledge spillovers.Acknowledgement The author would like to thank an anonymous referee for his valuable comments.     

Compatibility of expected utility and <Emphasis Type="Italic">μ/σ</Emphasis> approaches to risk for a class of non location–scale distributions

Proofs of compatibility of the expected utility and μ/σ approaches to incorporating uncertainty in decision making exist for at least some utility functions and location–scale distributions. But there are severe constraints and it is desirable to investigate compatibility more widely. We do so for the class of distributions that are transformable to location–scale form by concave transformation and where the utility functions remain concave under transformation. The class is important, containing distributions such as the lognormal and Pareto, usually considered more appropriate for modelling income or wealth than those in the location–scale family. We are grateful to Jack Meyer for very helpful comments and discussions and also to an anonymous referee for useful remarks.     

Revealed preference and differentiable demand

Summary. We prove that, for finitely many demand observations, the Strong Axiom of Revealed Preference tests not only the existence of a strictly concave, strictly monotone and continuous utility generator, but also one that generates an infinitely differentiable demand function. Our results extend those of previous related results (Matzkin and Richter, 1991; Chiappori and Rochet, 1987), yielding differentiable demand functions but without requiring differentiable utility functions.Received: 1 November 2001, Revised: 5 February 2004, JEL Classification Numbers: D11, D12. Correspondence to: Kam-Chau WongThis is a much revised version of Lee and Wong (2001). We are grateful to the Referee for valuable suggestions. We also thank Professor Marcel K. Richter for his comments.     

Subjective evaluations of n-person games

Using an axiomatization of subjective expected utility due to Fishburn, we characterize a class of utility functions over a set of n-person games in characteristic-function form. A probabilistic value is defined as the expectation of some player's marginal contribution with respect to some probability measure on the set of coalitions of other players. We decribe conditions under which a utility function on the set of n-person games is a probabilistic value; we prove as well an analogous result for simple games. We present additional axioms that characterize the semivalues and, in turn, the Shapley and Banzhaf values.     

Probabilistic dominance and status quo bias

Decision makers have a strong tendency to retain the current state of affairs. This well-documented phenomenon is termed status quo bias. We present the probabilistic dominance approach to status quo bias: an alternative is considered acceptable to replace the status quo only if the chances of a (subjectively) severe loss, relative to the status quo, are not too high. Probabilistic dominance is applied and behaviorally characterized in a choice model that allows for a range of status quo biases, general enough to accommodate unanimity, but also standard expected utility maximization. We present a comparative notion of “revealing more bias towards the status quo” and study its implications to the probabilistic dominance model of choice. Lastly, the model is applied to the endowment effect phenomenon and to a problem of international portfolio choice when investors are home biased.     

The Troika paradox

In three binary choice problems, people reveal a choice pattern which falsifies expected utility theory and many generalized non-expected utility theories. This new paradox challenges popular non-expected utility models analogously to how the Allais paradox challenged neoclassical expected utility theory.     

基于信息修正的非期望效用模型

人们对事件发生的可能性存在着主观判断。在不同的概率区间,人们对概率变化的敏感度是不一样的。传统的期望效用理论忽视了决策者对概率的主观反应,无法准确描述风险决策行为。基于信息修正的非期望效用模型,将客观概率转换成主观决策权重,可以弥补期望效用模型在捕捉决策者对概率主观反应方面的缺陷;同时,利用基于信息修正的非期望效用模型,通过量化人们在购买保险或股票时对风险的主观概率判断,可以对人们的保险需求和证券投资行为作出更好的解释或预测。     

A revealed-preference implication of weighted utility decisions under uncertainty

Summary. In a novel formulation of revealed preference analysis, Green and Osband [8] show that for expected-utility maximizers, acts partition the state-simplex into linear polyhedral blocks. The question naturally arises whether this characterization distinguishes expected utility theory from non-expected utility theories. This paper investigates the weighted utility theory of Chew [2] and shows that the corresponding partition is systematically different from the expected utility theory: the boundaries of the partition blocks are quadratic rather than linear. This result contains useful empirical contents. Received: May 15, 1995; revised version: November 22, 1996     

A Revealed Preference Theory for Non-expected Utility on "Certain × Uncertain" Consumption Pairs

In this paper we consider a two-period decision problem, where the feasible set is the set of "certain × uncertain" consumption pairs. That is, the decision-maker chooses ( x , m ) in a feasible set, where x is a certain first-period consumption and m is a random second-period consumption, a Borel probability measure on the set of real numbers. The purpose of this paper is to present revealed preference theory for non-expected utility on "certain × uncertain" consumption pairs. We present necessary and sufficient conditions for the data to be consistent with some non-expected utility functions.
JEL Classification Numbers: D11, D81, D91     

Stochastic dominance and behavior towards risk: The market for Internet stocks

Internet stocks registered large gains in the late 1990s, followed by large losses from early 2000. Using stochastic dominance theory, we infer how investor risk preferences have changed over this cycle, and relate our findings to utility theory and behavioral finance. Our major findings are as follows. First, risk averters and risk seekers show a distinct difference in preference for Internet versus “old economy” stocks. This difference is most evident during the bull market period (1998–2000) where Internet stocks stochastically dominate old economy stocks for risk seekers but not risk averters. In the bear market, risk averters show an increased preference for old economy stocks, while risk seekers show a reduced preference for Internet stocks. These results are inconsistent with prospect theory and indicate that investors exhibit reverse S-shaped utility functions.     

The value of a stochastic information structure

Upon observing a signal, a Bayesian decision maker updates her probability distribution over the state space, chooses an action, and receives a payoff that depends on the state and the action taken. An information structure determines the set of possible signals and the probability of each signal given a state. For a fixed decision problem, the value of an information structure is the maximal expected utility that the decision maker can get when the observed signals are governed by this structure. Thus, every decision problem induces a preference order over information structures according to their value. We characterize preference orders that can be obtained in this way. We also characterize the functions defined over information structures that measure their value.     

Market equilibrium with heterogeneous recursive-utility-maximizing agents

Summary This paper considers a heterogeneous agent Lucas style exchange economy. For a class of recursive utility functions containing the standard additive expected utility functions, I demonstrate that there exist market equilibria characterized by stationary (ergodic) Markov processes for consumption, portfolio holdings, asset prices and the unobserved utilities. No assumptions about market completeness are made, and there are no restrictions on the underlying information filtration.Other contributions of this paper include: (i) an existence and uniqueness theorem of intertemporal utility for the general class of recursive generators; (ii) the optimum principle as well as its corresponding Euler equation derived for the agent's consumption and portfolio choice problem under recursive utility, and (iii) a single-agent equilibrium asset pricing formula which generalizes that of Epstein and Zin (1989).This paper is a part of my PhD dissertation at the University of Toronto. I would like to thank Larry Epstein for his enthusiastic supervision, helpful discussion and valuable comments. Thanks also to Tan Wang and especially Darrell Duffie for valuable comments.     

Ethnic groups and the Heckscher-Ohlin-Samuelson trade model

Summary In this paper, we report a mode of the Harris-Todaro variety in which the labor force is composed of distinct and easily identifiable ethnic groups and in which capital is intersectorally mobile. We extend the central theorems of Heckscher-Ohlin-Samuelson trade theory to our model and also relate our results to other work.This work was conceived over several visits to The Pakistan Institute of Development Economics and finished at Berkeley where it was first presented at Professor Bardhan's Workshop in Development Economics. I am grateful to Professor Bardhan and to Director Naqvi and other Officers of the Institute for their hospitality and interest. I am also grateful to Naeem Siddiqui and Ray Reizman for several useful conversations; to S. Broca for many provocative comments on the HOS trade model; and, in particular, to one of three anonymous referees for her/his careful reading and detailed comments.     

Maxmin under risk

Summary. Let be a continuous and convex weak order on the set of lotteries defined over a set Z of outcomes. Necessary and sufficient conditions are given to guarantee the existence of a set of utility functions defined on Z such that, for any lotteries p and q, The interpretation is simple: a conservative decision maker has an unclear evaluation of the different outcomes when facing lotteries. She then acts as if she were considering many expected utility evaluations and taking the worst one. Received: January 19, 2000; revised version: December 20, 2000     

Is Kreps-Porteus utility distinguishable from intertemporal expected utility?

Summary In a Lucas (1978) model, with a Kreps-Porteus (1978) nonexpected utility, the following property of equilibrium holds generically in the space of finite-state, Markov output growth rate processes: equilibrium price of equity is distinct from that implied by any intertemporally additive expected utility satisfying specified regularity conditions. In that sense the more general utility functions are observationally distinguishable from the standard expected utility specification.I would like to thank Larry G. Epstein for posing to me the problem studied in this paper and for many suggestions and comments. I am also grateful to Darrell Duffie for helpful suggestions. I am responsible for errors. This papers is part of my Ph.D. thesis at University of Toronto.     

Epistemic Conditions for Equilibrium in Beliefs without Independence

Aumann and Brandenburger [Econometrica63(1995), 1161–1180.] provide sufficient conditions on the knowledge of the players in a game for their beliefs to constitute a Nash equilibrium. They assume, among other things, mutual knowledge of rationality. By rationality of a player, it is meant that the action chosen by him maximizes his expected utility, given his beliefs. There is, however, no need to restrict the notion of rationality to expected utility maximization. This paper shows that their result can be generalized to the case where players' preferences over uncertain outcomes belong to a large class of non-expected utility preferences.Journal of Economic LiteratureClassification Numbers: C72, D81.     

Rate-of-return dominance and efficiency in an experimental economy

Summary. One of the main challenges for monetary economics is to explain the use of assets that are dominated in rate-of-return as media of exchange. We use experimental methods to study how a fiat money might come to be used in transactions when an identically marketable, dividend-bearing asset, a consol, is also available. Our experimental economies, which have an overlapping generations structure, have the property that the only stationary rational expectations equilibria (SREE) require exclusive use of the consol as the medium of exchange. In a baseline treatment, agents use the consol exclusively, as would occur in an SREE. However, in other treatments, we observe episodes of rate-of-return dominance,with consistent use of fiat money as a medium of exchange. The results show that two properties of our economies are associated with the rate of return dominance anomaly. The first is a history of trading with fiat money, prior to the introduction of the consol. The second is the timing of the dividend payment; when the dividend payment follows the execution of trades between generations, hoarding of the consol occurs on the part of the old, who earn dividends by hoarding. In our economies, settling transactions with a dividend-bearing asset does not improve allocations over those resulting from trading with fiat money. Received: July 11, 2002; revised version: July 25, 2002 RID="*" ID="*"We thank Anne Villamil, participants in the 2000 Purdue University Conference on Monetary Economics, the Summer 2000 meetings of the Economic Science Association, and a referee, for very helpful comments. We thank the Krannert School of Management and the Purdue University Center for International Business, Education and Research for financial support and Vivian Lei for research assistance. We also thank Ron Michener for referring us to the historical account of the early introduction of money into the American colonies, as reported by Benjamin Franklin. Correspondence to: G. Camera     

Core and equilibria under ambiguity

This paper introduces new core and Walrasian equilibrium notions for an asymmetric information economy with non-expected utility preferences. We prove existence and incentive compatibility results for the notions we introduce. We also discuss a framework for ex ante, interim and ex post preferences.     

Envy and Altruism: Contrasting Bivariate and Univariate Prospect Preferences

We compare prospect ordering with and without envy and altruism. We find that envy can induce a violation of the univariate first‐degree stochastic dominance (FSD), and thus a violation of the classic expected utility monotonicity axiom. Surprisingly, altruism can also violate FSD preferences. The intuitive explanation of the result in the case of altruism hinges on the sign of the mixed derivative of the bivariate preference: the individual might prefer a certain correlation between her wealth and her peer group's wealth, and is therefore willing to violate FSD as long as the outcomes of the two parties are ordered according to her preferences. When investments are considered, envy and altruism can distort not only preferences but also actual choices.