Voting in assemblies of shareholders and incomplete markets

Summary. An economy with two dates is considered, one state at the first date and a finite number of states at the last date. Shareholders determine production plans by voting - one share, one vote - and at -majority stable stock market equilibria, alternative production plans are supported by at most percent of the shareholders. It is shown that a -majority stable stock market equilibrium exists if where S is the number of states at the last date and J is the number of firms. Moreover, an example shows that -majority stable stock market equilibria need not exist for smaller s.Received: 23 December 2002, Revised: 14 June 2004, JEL Classification Numbers: D21, D52, D71, G39. Correspondence to: Hervé CrésThe authors are grateful to an anonymous referee for helpful comments and suggestions. Financial support from the Danish Research Councils and hospitality of HEC is gratefully acknowledged by Mich Tvede and support from Fondation HEC is gratefully acknowledged by Hervé Crés.     

Stationary measures for some Markov chain models in ecology and economics

Summary. Let continuous, exists in for x in . Let be an i.i.d. sequence from F and X₀ be a nonnegative random variable independent of . Let be the Markov chain generated by the iteration of random maps by . Such Markov chains arise in population ecology and growth models in economics. This paper studies the existence of nondegenerate stationary measures for {X_n}. A set of necessary conditions and two sets of sufficient conditions are provided. There are some convergence results also. The present paper is a generalization of the work on random logistics maps by Athreya and Dai (2000).Received: 20 March 2002, Revised: 4 December 2002, JEL Classification Numbers: C22, D9.The author wishes to thank Professor Mukul Majumdar and the referees for several useful suggestions.     

Stationary Markov equilibria for overlapping generations

Summary.  At a stationary Markov equilibrium of a Markovian economy of overlapping generations, prices at a date-event are determined by the realization of the shock, the distribution of wealth and, with production, the stock of capital. Stationary Markov equilibria may not exist; this is the case with intra-generational heterogeneity and multiple commodities or long life spans. Generalized Markov equilibria exist if prices are allowed to vary also with the realization of the shock, prices and the allocation of consumption and production at the predecessor date-event. (Stationary) Markov -equilibria always exist; as allocations and prices converge to equilibrium prices and allocations that, however, need not be stationary.Received: 2 March 2004, Revised: 2 April 2004, JEL Classification Numbers:   D50, D52, D60, D80, D90.Correspondence to: Felix KublerWe thank participants in seminars in Athens and Lund, at Penn, at IMPA and at Stanford, the 2002 CEME (NBER) General Equilibrium Conference and the 2002 SED meetings, and especially Martin Hellwig, George Mailath and an anonymous referee for very helpful comments.     

The nature of the steady state in models of optimal growth under uncertainty

Summary. We study a one-sector stochastic optimal growth model with a representative agent. Utility is logarithmic and the production function is of the Cobb-Douglas form with capital exponent . Production is affected by a multiplicative shock taking one of two values with positive probabilities p and 1-p. It is well known that for this economy, optimal paths converge to a unique steady state, which is an invariant distribution. We are concerned with properties of this distribution. By using the theory of Iterated Function Systems, we are able to characterize such a distribution in terms of singularity versus absolute continuity as parameters and p change. We establish mutual singularity of the invariant distributions as p varies between 0 and 1 whenever . More delicate is the case . Singularity with respect to Lebesgue measure also appears for values such that . For and Peres and Solomyak (1998) have shown that the distribution is a.e. absolutely continuous. Characterization of the invariant distribution in the remaining cases is still an open question. The entire analysis is summarized through a bifurcation diagram, drawn in terms of pairs .Received: 9 April 2002, Revised: 29 October 2002, JEL Classification Numbers: C61, O41.Correspondence to: Tapan MitraThis research was partially supported by CNR (Italy) under the "Short-term mobility" program and by M.U.R.S.T. (Italy) National Group on "Nonlinear Dynamics and Stochastic Models in Economics and Finance" . We are indebted to Rabi Bhattacharya for providing us with the reference to Solomyak's (1995) paper. The present version has benefitted from comments by Mukul Majumdar and two anonymous referees.     

The extent of the market and optimal specialization

Summary. In this paper I examine how the socially optimal allocation, and specialization in particular, depends on the extent of the market. I interpret the societys ability to keep transaction records as the extent of the market and measure it by a probability with which the society can update agents past transactions into the public record. The society uses this record to detect potential defections from the optimal allocation and to punish the defectors with autarky. I show that when is small, increasing increases optimal specialization. However, when is close to 1, increasing further has no effect on the optimal allocation. I also show that optimal specialization is gradual over time when there is cost to reduce specialization. Even for small , the process converges to the unconstrained optimum that would occur under .JEL Classification Numbers: D60, C78.An earlier version of this paper was presented at the Society for Economic Dynamics meetings in Stockholm (2001). I thank a referee and the editor for useful comments and suggestions. For financial support, I gratefully acknowledge the Social Sciences and Humanities Research Council of Canada, and the Bank of Canada Fellowship. The opinion expressed here is my own and does not reflect the view of the Bank of Canada.     

More pessimism than greediness: a characterization of monotone risk aversion in the rank-dependent expected utility model

Summary. This paper studies monotone risk aversion, the aversion to monotone, mean-preserving increase in risk (Quiggin [21]), in the Rank Dependent Expected Utility (RDEU) model. This model replaces expected utility by another functional, characterized by two functions, a utility function u in conjunction with a probability-perception function f. Monotone mean-preserving increases in risk are closely related to the notion of comparative dispersion introduced by Bickel and Lehmann [3,4] in Non-parametric Statistics. We present a characterization of the pairs (u,f) of monotone risk averse decision makers, based on an index of greediness G _u of the utility function u and an index of pessimism P _f of the probability perception function f: the decision maker is monotone risk averse if and only if . The index of greediness (non-concavity) of u is the supremum of taken over . The index of pessimism of f is the infimum of taken over 0 < v < 1. Thus, , with G _u = 1 iff u is concave. If then , i.e., f is majorized by the identity function. Since P _f = 1 for Expected Utility maximizers, forces u to be concave in this case; thus, the characterization of risk aversion as is a direct generalization from EU to RDEU. A novel element is that concavity of u is not necessary. In fact, u must be concave only if P _f = 1.Received: 10 April 2001, Revised: 18 November 2003, JEL Classification Numbers: D81. Correspondence to: Michéle CohenAlain Chateauneuf, Michéle Cohen, Isaac Meilijson: We are most grateful to Mark Machina, Peter Wakker and two anonymous referees for very helpful suggestions and comments.     

Location-then-price competition with uncertain consumer tastes

Summary. We investigate Hotellings duopoly game of location-then-price choices with quadratic transportation costs and uniformly distributed consumers under the assumption that firms are uncertain about consumer tastes. When the uncertainty has a uniform distribution on the closed interval , with , we characterize the unique equilibrium and the socially optimal locations. Contrary to the individual-level random utility models, we find that uncertainty is a differentiation force. For small (large) sizes of the uncertainty, there is excessive (insufficient) differentiation. More uncertainty about consumer tastes can have positive or negative welfare effects, depending on the size of the uncertainty.Received: 1 February 2003, Revised: 1 April 2004, JEL Classification Numbers: C72, D43, D81, L10, L13, R30, R39. Correspondence to: Kieron J. MeagherWe thank Simon Anderson, Jörg Borrmann, Vince Crawford, Bernd Engelmann, Catherine de Fontenay, Simon Grant, Stephen King, Preston McAfee, John Miller, Scott Page, Rohan Pitchford, Bill Schworm, Joel Sobel, an anonymous referee and seminar participants at CALTECH and at the 1999 Econometric Society Winter Meetings for their comments and criticisms. Zauner was affiliated with the Department of Economics, University of Sydney, during the earlier stages of this project.     

Random continued fractions: a Markov chain approach

Summary. By allowing the numbers appearing in a continued fraction to be random, one gets what are called random continued fractions. Under fairly general conditions, including the case when the random variables are i.i.d. non-negative, random continued fractions converge with probability one. A markovian algorithm seems to play a crucial role in studying the distribution of random continued fractions. This Markov Chain on is generated by iteration of random monotone decreasing maps on S and the connection comes from the fact that the distribution of random continued fraction is obtained as an invariant probability of the Markov Chain. Using the splitting condition, it is shown that the distribution of the Markov Chain converges exponentially fast in the Kolmogorov distance to an unique invariant probability , which is shown to be non-atomic, except in the degenerate case. A sufficient condition is given for the invariant probability to have full support S. In some special cases, the invaraint probability is obtained explicitly and this includes one case when the probability turns out to be a singular non-atomic probability with full support S. Extensions of some results to higher dimensions are also discussed.Received: 22 May 2002, Revised: 9 September 2002, Subject Classification Numbers: 60F05, 60J05.Alok Goswami: I would like to thank Rabi Bhattacharya for useful discussions at the time of writing this paper. Thanks are also due to the referee for offering various suggestionsfor improvement over a previous draft of the paper.     

The fuzzy core and the (\Pi, \beta)-balanced core

Summary. This note provides a new proof of the non-emptiness of the fuzzy core in a pure exchange economy with finitely many agents. The proof is based on the concept of -balanced core for games without side payments due to Bonnisseau and Iehlé (2003).Received: 8 May 2003, Revised: 8 August 2004, JEL Classification Numbers: D51, C71.Helpful comments of Jean-Jacques Herings and Hans Peters are gratefully acknowledged.     

The Zilcha criterion for dynamic inefficiency

Summary. This paper reexamines the condition (1 + n), which Zilcha (1991) presents as a necessary and sufficient condition for dynamic inefficiency of stationary allocations in overlapping generation models with stochastic production. We show that this condition is necessary but not sufficient for a stationary allocation to be dynamically inefficient by Zilchas definition. We also show that there is a narrow but widely studied class of specifications in which the Zilcha test is both necessary and sufficient for dynamic inefficiency of stationary competitive equilibrium allocations. Outside this class, however, counterexamples can be constructed relatively easily.Received: 30 September 2002, Revised: 13 August 2004, JEL Classification Numbers: D51, D90, E13, E22. Correspondence to: Steven RussellWe thank Jon Burke, Subir Chakrabarti, Itzhak Zilcha and an anonymous referee for helpful conversations and/or comments.     

Infinite inequality systems and cardinal revelations

Summary. Many economics problems are maximization or minimization problems, and can be formalized as problems of solving linear difference systems of the form and r _k -r _l > c _kl , for r-unknowns, with given c-constants. They typically involve strict as well as weak inequalities, with infinitely many inequalities and unknowns. Since strict inequalities are not preserved under passage to the limit, infinite systems with strict inequalities are notoriously hard to solve. We introduce a unifying tool for solving them. Our main result (Theorem 1 for the countable case, Theorem [2] for the not-necessarily-countable case) introduces a uniform solvability criterion (the -Axiom), and our proof yields a method for solving those that are solvable. The axioms economic intuition extends the traditional ordinal notion of revealed preference to a cardinal notion. We give applications in producer theory, consumer theory, implementation theory, and constrained maximization theory.Received: 21 May 2003, Revised: 29 October 2004, JEL Classification Numbers: C69, D21, D11, D82. Correspondence to: Marcel K. RichterWe thank Professor Leonid Hurwicz for helpful discussions, and a referee for helpful comments.     

Continuity properties of the private core

Let be a sequence of differential information economies, converging to a limit differential information economy (written as ). Denote by the set of all ε-private core allocations, ε ≥ 0 (for ε=0 we get the private core of Yannelis (1991), denoted by ). Under appropriate conditions, we prove the following stability results

Knowledge-independent Invariance Rules for Copula Duration in Dungflies

In dung flies, copula duration decreases, and the proportional rate of sperm transfer increases, as male body size becomes larger. From a marginal value approach to optimal copula duration, we show that these relationships result in the product, , remaining approximately constant across the range of male body size. The expected proportion of a female's eggs fertilized by a copulating male, equivalent to 1 – e^–c·t , is likewise invariant with male body size. (Overbars and refer to the averages over female sizes). We assume that the information or cues a male can perceive about females forms a set of discrete recognition categories, each of which is uniquely recognizable by a male, but within which he cannot discriminate. There are then likely to be different male optima for the product between categories. But the invariance rules still hold within categories, independently of exactly what the recognition categories are, provided that all males perceive the same categories. For example, suppose that males of all sizes categorise females as either 'large', 'medium', or 'small'. Then though the optimal male strategy (product ) for (say) 'large' females may differ from the corresponding optima for the other two categories, it remains constant with male size across all the 'large' females. Further, the product should remain constant for all male sizes if we take the average across all females, or across any subset of recognition categories. We believe that these conclusions have general applicability and implications for optimal foraging under the marginal value theorem, and demonstrates how we can sometimes make predictions (e.g. the relation between copula duration and male body size in dungflies) without determining exactly what a forager 'knows'.     

From “tax state” to “debt state”

The paper is motivated by Joseph A. Schumpeter's The Crisis of the Tax State. It inquires whether the buildup of government debt in peacetimeprosperity is a threat to the stability, existence or creation of viable tax states. The paper begins by setting out Schumpeter's conception of the tax state and the nature of recent political-economic events which have reinvigorated the concept. Next the paper sets out some simple debt dynamics and sketches a debt-induced business cycle arising from heavy reliance on debt finance in peacetimeprosperity. Finally, the paper assesses threats to the tax state in light of recent work on path dependence and positive feedback. An attempt is made to throw some light on whether the plethora of new, and often small, states spawned by the demise of communism can be viable tax states.Essay on Government, the Tax State and Economic Dynamics submitted to the Third Schumpeter Prize Competition.     

The structure of the Nash equilibrium sets of standard 2-player games

Summary. In this paper I study a class of two-player games, in which both players action sets are [0,1] and their payoff functions are continuous in joint actions and quasi-concave in own actions. I show that a no-improper-crossing condition is both necessary and sufficient for a finite subset A of to be the set of Nash equilibria of such a game.Received: 21 November 2002, Revised: 9 September 2004, JEL Classification Numbers: C65, C72.I am grateful to an editor of the journal and an anonymous referee for their very helpful comments. I also would like to thank the seminar participants at City University of Hong Kong, Georgia State University, Northwestern University, and Rice University.     

Equilibria and Pareto optima of markets with adverse selection

Summary This paper examines the efficiency properties of competitive equilibrium in an economy with adverse selection. The agents (firms and households) in this economy exchange contracts, which specify all the relevant aspects of their interaction. Markets are assumed to be complete, in the sense that all possible contracts can, in principle, be traded. Since prices are specified as part of the contract, they cannot be used as free parameters to equate supply and demand in the market for the contract. Instead, equilibrium is achieved by adjusting the probability of trade. If the contract space is sufficiently rich, it can be shown that rationing will not be observed in equilibrium. A further refinement of equilibrium is proposed, restricting agents' beliefs about contracts that are not traded in equilibrium. Incentive-efficient and constrained incentive-efficient allocations are defined to be solutions to appropriately specified mechanism design problems. Constrained incentive efficiency is an artificial construction, obtained by adding the constraint that all contracts yield the same rate of return to firms. Using this notion, analogues of the fundamental theorems of welfare economics can be proved: all refined equilibria are constrained incentive-efficient and all constrained incentive-efficient allocations satisfying some additional conditions can be decentralized as refined equilibria. A constrained incentive-efficient equilibrium is typically not incentive-efficient, however. The source of the inefficiency is the equilibrium condition that forces all firms to earn the same rate of return on each contract.Notation ={ ₁,..., _k } set of outcomes - : ₊ generic contract or lottery - A = () ; - A_o A{, where denotes the null contract or no trade - S={1,...,¦S¦} set of seller types - L(s) number of type-s sellers - M number of buyers - u: × S seller's utility function, which can be extended toA× S by puttingu(, s) ; - v. × S buyer's utility function, which can be extended toA × S by puttingv(, s) ; - f:A ₀ ×S ₊ allocation of sellers - g:A ₀ ×S ₊ allocation of buyers - A ₊ sellers' trading function - :A ×S ₊ buyers' trading function This paper has had a long gestation period, during which I have been influenced by helpful conversations with many persons, by their work, or both. Among those who deserve special mention are Martin Hellwig, Roger Myerson, Edward Prescott, Robert Townsend and Yves Younés. Earlier versions were presented to the NBER/CEME Conference on Decentralization at the University of Toronto and the NBER Conference on General Equilibrium at Brown University. I would like to thank John Geanakoplos, Walter Heller, Andreu Mas Colell, Michael Peters, Michel Poitevin, Lloyd Shapley, John Wooders, Nicholas Yannelis and an anonymous referee for their helpful comments and especially Robert Rosenthal for his careful reading of two drafts. The financial support of the National Science Foundation under Grant No. 912202 is gratefully acknowledged.     

On economic disequilibrium and free lunch

There is a sharp disagreement between mainstream economists and advocates of energy efficiency as regards the potential for free lunches or no regrets policies to cut greenhouse gas emissions. From an economics perspective, the critical question is whether the economic system is — or is not — close to a Pareto-optimum equilibrium state. If so, it follows that most technological systems now in place are optimum, or nearly so, from an economic perspective. If not, there may be many sub-optimal technologies in place, with corresponding opportunities for very high returns on appropriate investments. This paper presents some of the evidence supporting the latter thesis.     

“Buy Domestic” Campaigns and Optimal Tariffs

This paper attempts to analyze the strategic use of optimal tariffs and to examine the effects of national bias on the optimal trade policy and social welfare in a two-country, two-good, price competition model derived from Neven et al. (1991). The major findings are as follows. (1) If all consumers prefer the domestic good, then buy domestic campaigns will decrease the prohibitive tariff rate and increase local welfare. (2) If at least some consumers prefer the foreign good, but not to a great extent, then buy domestic campaigns will not change the optimal tariff rate, but may improve local welfare. (3) When all consumers greatly prefer the foreign good, then promotion of buy domestic decreases the optimal tariff rate, but it cannot improve social welfare. With this framework, we also prove that buy domestic campaigns serve as a substitute for tariffs with respect to a strategic trade policy.