Subjective recursive expected utility

We axiomatize a subjective version of the recursive expected utility model. This development extends the seminal results of Kreps and Porteus (Econometrica 46:185–200 (1978)) to a subjective framework and provides foundations that are easy to relate to axioms familiar from timeless models of decision making under uncertainty. Our analysis also clarifies what is needed in going from a represention that applies within a single filtration to an across filtration representation.Part of this research was conducted when Ozdenoren visited MEDS in Fall 2003. We thank Tapas Kundu, Costis Skiadas, Jean-Marc Tallon and Tan Wang for helpful discussions and also thank audiences at Koc University, Northwestern University, the CERMSEM conference “ Mathematical Models in Decision Theory” at Universite Paris I, and the FUR XI conference on foundations and applications of utility, risk and decision theory     

Multiple Species Boreal Forests – What Faustmann Missed

Recent research in natural sciences shows that the dynamics in boreal forests are much more complex than what many models traditionally used in forestry economics reflect. This essay analyzes some challenges of accounting for such complexity. It shows that the optimal harvesting strategy for forest owners is history dependent and for some states of the forest, more than one strategy may be optimal.This paper confirms earlier literature on shallow lakes and coral reefs and shows that this kind of phenomena seem much more common than previously thought. They are valid for a wide range of ecosystems that cover large surfaces and they do not depend on the choice of some specific function to model the non-linearity. There are also indications that theses results could be obtained even for resources with concave growth if at least one species with non-linear growth affects their dynamics.     

Evolutionary foundations of aggregate-taking behavior

Summary. I show that aggregate-taking behavior is often evolutionarily stable for finite population in symmetric games in which payoff depends only on own strategy and an aggregate. I provide economic examples exhibiting this phenomenon. Received: August 27, 2001; revised version: January 29, 2002 RID="*" ID="*" The paper has profited from the comments of Maria Montero, Burkhard Hehenkamp, Wolfgang Leininger, and Dave Furth. Financial support from the DFG via Postgraduate Programme at the University of Dortmund and via SFB 504 at the University of Mannheim is acknowledged. RID="*" ID="*" Present address: University of Mannheim, SFB 504, L 13, 15, 68131 Mannheim, Germany (e-mail: possajen@sfb504.uni-mannheim.de)     

Medical insurance with rank-dependent utility

Summary. A well-known result in the medical insurance literature is that zero co-insurance is never second-best for insurance contracts subject to moral hazard. We replace the usual expected utility assumption with a version of the rank-dependent utility (RDU) model that has greater experimental support. When consumers exhibit such preferences, we show that zero co-insurance may in fact be optimal, especially for low-risk consumers. Indeed, it is even possible that the first-best and second-best contracts are identical. In this case, there is no “market failure”, despite the informational asymmetry. We argue that these RDU results are in better accord with the empirical evidence from US health insurance markets. Received: February 26, 2001; revised version: October 4, 2002 RID="*" ID="*"The authors would particularly like to thank Simon Grant, John Quiggin, Peter Wakker and an anonymous referee for valuable comments and suggestions on earlier drafts. The paper has also benefitted from the input of seminar audiences at The Australian National University, University of Auckland, University of Melbourne and University of Sydney. Ryan also gratefully acknowledges the financial support of the ARC, through Grant number A000000055. Correspondence to:R. Vaithianathan     

Changing rewards in contests: Has the three-point rule brought more offense to soccer?

In the mid-nineties FIFA decided to increase from two to three the number of points assigned to the winning team of a soccer match played under traditional round-robin national leagues. Since a game of soccer can be regarded as a contest, FIFA's measure provides an interesting case-study for analysing how a change in the system of rewards (from a zero to a non-zero sum rule) may affect the contestants' equilibrium behaviour. In this paper we try to assess, both theoretically and empirically, whether FIFA's new point rule has changed soccer towards a more offensive game, in which teams adopt more risky strategies. In particular, we evaluate the “na?ve hypothesis” according to which the measure would induce every team to play always more offensively, and we explore the extent to which the change in teams' behaviour may be affected by quality differentials between teams. Our most important hypothesis is that when the asymmetry between opposing teams is large enough, an increase in the reward for victory induces the weaker team to play more defensively, rather than the opposite. By looking at a subset of matches held in the Portuguese first division league, which approximate the conditions of our model, we find support for this hypothesis. First version received: July 1999/Final version received: May 2001     

Corporate governance in family-controlled firms in Taiwan

This paper examines the effects of ownership structure and board characteristics on performance in publicly traded Taiwanese firms that are controlled by founding families. Results show that when shares are owned by institutional investors, particularly foreign financial institutions, firms perform better. However, where families are the major shareholders, this is not the case. In addition, boards that are independent of the financial interests of the founding family have a positive impact on performance, whether measured by accounting ratios, operating performance or the stock market. (JEL: P52, G32)     

Structure,Clearinghouses and Symmetry

We introduce and justify a taxonomy for the structure of markets and minimal institutions which appear in constructing minimally complex trading structures to perform the functions of price formation, settlement and payments. Each structure is presented as a playable strategic market game and is examined for its efficiency, the number of degrees of freedom and the symmetry properties of the structure     

Probability of survival in a random exchange economy with dependent agents

Summary. In this paper I analyze the general equilibrium in a random Walrasian economy. Dependence among agents is introduced in the form of dependency neighborhoods. Under the uncertainty, an agent may fail to survive due to a meager endowment in a particular state (direct effect), as well as due to unfavorable equilibrium price system at which the value of the endowment falls short of the minimum needed for survival (indirect terms-of-trade effect). To illustrate the main result I compute the stochastic limit of equilibrium price and probability of survival of an agent in a large Cobb-Douglas economy. Received June 7, 2001; revised version: January 7, 2002 RID="*" ID="*" I would like to thank Mukul Majumdar and Thomas DiCiccio for helpful discussion and an anonymous referee for valuable comments and suggestions.