Decentralizing lottery allocations in markets with indivisible commodities

Summary In economies with indivisible commodities, consumers tend to prefer lotteries in commodities. A potential mechanism for satisying these preferences is unrestricted purchasing and selling of lotteries in decentralized markets, as suggested in Prescott and Townsend [Int. Econ. Rev.25, 1–20]. However, this paper shows in several examples that such lottery equilibria do not always exist for economies with finitely many consumers. Other conditions are needed. In the examples, equilibrium and the associated welfare gains are realized if consumptions are bounded or if lotteries are based upon a common sunspot device as defined by Shell [mimeo, 1977] and Cass and Shell [J. Pol. Econ.91, 193–227]. The paper shows that any lottery equilibrium is either a Walrasian equilibrium or a sunspot equilibrium, but there are Walrasian and sunspot equilibria that are not lottery equilibria.This paper is based on Chapter 3 of my doctoral dissertation, written while I was a student at Cornell University. I thank Larry Blume, Yue Yun Chen, David Easley, Aditya Goenka, John Marshall, Bruce Smith, John Wooders and an anonymous referee. I am particularly grateful to Karl Shell and Cheng-Zhong Qin. I thank the Academic Senate at UCSB for financial support.     

On the theory of cost sharing

This paper investigates efficiency and equitability issues given a cost sharing method in an economy with a public commodity. We study the concept of a -cost share equilibrium and examine the set of all equilibrium allocations. Finally, we devise a mechanism to implement -cost share equilibria as strong equilibria of an associated non-cooperative game.This paper was written while Shlomo Weber was visiting the University of Bonn. Financial support from theSonderforschungsbereich 303 is gratefully acknowledged. We also would like to thank Dieter Bös for valuable comments.     

Strategic market games with a finite horizon and incomplete markets

Summary. We study a strategic market game associated to an intertemporal economy with a finite horizon and incomplete markets. We demonstrate that generically, for any finite number of players, every sequentially strictly individually rational and default-free stream of allocations can be approximated by a full subgame-perfect equilibrium. As a consequence, imperfect competition may Pareto-dominate perfect competition when markets are incomplete. Moreover - and this contrasts with the main message conveyed by the market games literature - there exists a large open set of initial endowments for which full subgame-perfect equilibria do not converge to -efficient allocations when the number of players tends to infinity. Finally, strategic speculative bubbles may survive at full subgame-perfect equilibria.Received: 24 January 2002, Revised: 21 February 2003, JEL Classification Numbers: C72, D43, D52. Correspondence to: Gaël GiraudWe thank Tim Van Zandt for his comments.     

Asymmetric Factor Substitutability and Indeterminacy

We consider a discrete-time two-sector CES economy with sector specific external effects in which factor substitutability differs across sectors. For this general model, we provide sufficient conditions on the elasticities of capital/labor substitution for local indeterminacy of equilibria.Acknowledgement We would like to thank two anonymous referees, the editor Dieter Bös and Tapan Mitra for comments on an earlier version of this paper, previously entitled Capital Depreciation, Factors Substitutability and Indeterminacy, which allowed us to improve considerably the results.     

Economic progress and skill obsolescence with network effects

Summary. We construct an OLG model with network effects to examine skill obsolescence when individuals can choose technological vintages. In the absence of transfer payments, some regions of the parameter space have unique stationary equilibria, others have unique cyclical equilibria, and others have multiple stationary equilibria. All equilibria are Pareto efficient. However, rat race equilibria can exist in which all agents currently alive prefer a slower rate of progress than occurs in equilibrium. When contemporaneous transfers are allowed, equilibria are unique everywhere, but a cycle still exists, and a rat race can still arise in equilibrium. Allowing intertemporal transfers (debt) ensures that all equilibria are stationary. In the relevant parameter range, the introduction of debt can eliminate cycles and increase the long-run growth rate. No rat race equilibria exist when debt is allowed.Received: 3 January 2002, Revised: 3 June 2004, JEL Classification Numbers: 041, J24, O33. Correspondence to: Ian P. KingEarly versions of this paper were presented at the West Coast Macro Workshop, the Mid-West Macro Meetings, the Canadian Macroeconomics Study Group Meetings, and the Society for Economic Dynamics Meetings. We would like to thank V. V. Chari, Merwan Engineer, Don Ferguson, John Hillas, John Knowles, Dan Peled, Dan Usher, Linda Welling and Julian Wright for helpful comments. We are especially grateful to an anonymous referee for some very useful and substantive comments.     

Competitive equilibria in overlapping generations Experiments

Summary The paper presents the results of four overlapping generations experiments performed at the California Institute of Technology. Overlapping generations markets were created in which each agent had a two period life span. With the exception of the first period, there were eight agents trading in each period; four buyers (two young and two old) and four sellers (two young and two old). Parameters were selected so that a small set of equilibria existed. The markets were open for twenty-nine periods with a demand shift occurring at the fifteenth and sixteenth periods.This work provides a method of computing all competitive equilibria for a class of environments—called the opposing shift environments. The main conclusion of the experiments is that the experimental price data converge to near the stationary portions of the competitive equilibria. Demographic dynamics are also explored as part of the price adjustment process. Dynamic features found in non-overlapping environments are also observed in the overlapping generations case.We thank E. J. Nanale, a Caltech undergraduate student, who helped design and conduct the experiments. Special thanks are due to Hsing Yang Lee for his help in adapting the Multiple Unit Double Auction Program to accomodate the overlapping generations environment and for his help with the data processing. We also thank David Grether who found a serious problem with the statistical analysis in an early draft. The research assistance of Kay-Yut Chen was also very valuable to the completion of this work. The comments and suggestions of P. Rangazas were very helpful. The research of the second author was supported in part by a National Science Foundation Grant and the California Institute of Technology Laboratory for Experimental Economics and Political Science.     

Sunspot equilibria and the transfer paradox

Summary. We show that for international economies with two countries, in which agents have additively separable utility functions, the existence of sunspot equilibria is equivalent to the occurrence of the transfer paradox. This equivalence enables us to provide some new insights on the relation of the existence of sunspot equilibria and the multiplicity of spot market equilibria.Received: 1 October 2003, Revised: 1 April 2004, JEL Classification Numbers: C62, D52, F3, F20, 012.Correspondence to: Thorsten HensWe would like to thank Anke Gerber for carefully checking and improving our arguments. Moreover, we are grateful to Piero Gottardi for his encouragement and his comments, to Andreu Mas-Colell and Mike Jerison for very fruitful discussions and to Klaus Schenk-Hoppé for his support in using . All remaining errors are ours.     

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.     

Technological change, human capital update and growth policies

This paper presents a model of growth driven simultaneously by innovation and human capital accumulation. Two different long-run equilibria are possible, according to whether or not workers skills are completely updated over time as knowledge expands. Skill gaps could arise as a consequence of poor education infrastructures, even in the efficient solution; in such circumstances, we find that whilst education policies are able to encourage growth, R&D policies are not. Otherwise, subsidizing education becomes ineffective for enhancing growth, although it could be necessary to avoid possible skill gaps originated by the R&D growth-enhancing policy.JEL Classification: O41, O33The authors wish to thank the financial support received for the project SEC 2001-2469 (Ministry of Science and Technology, Spain, and FEDER), as well as the comments of the co-editor and the referees.     

Mistaken self-perception and equilibrium

Summary. Motivated by real-world information economics problems and by experimental findings on overconfidence, this paper introduces a general epistemic construction to model strategic interaction with incomplete information, where the players self-perception may be mistaken. This allows us to rigorously describe equilibrium play, by formulating appropriate equilibrium concepts. We show that there always exist objective equilibria, where the players correctly anticipate each others strategies without attempting to make sense of them, and that these outcomes coincide with the equilibria of an associated Bayesian game with subjective priors. In population games, these equilibria can also be always introspectively rationalized by the players, despite their possibly mistaken self-perception.Received: Received: May, 12, 2003; revised version: 3 December 2004, Revised: 3 December 2004, JEL Classification Numbers: J31, D82, D83.I thank Massimiliano Amarante, Eddie Dekel, Massimo Marinacci, Jean Francois Mertens, Giuseppe Moscarini, Paolo Siconolfi, Marciano Siniscalchi, Joel Sobel, and an anonymous referee.     

Are incomplete markets able to achieve minimal efficiency?

Summary. We consider economies with incomplete markets, one good per state, two periods, t = 0,1, private ownership of initial endowments, a single firm, and no assets other than shares in this firm. In Dierker, Dierker, Grodal (2002), we give an example of such an economy in which all market equilibria are constrained inefficient. In this paper, we weaken the concept of constrained efficiency by taking away the planners right to determine consumers investments. An allocation is called minimally constrained efficient if a planner, who can only determine the production plan and the distribution of consumption at t = 0, cannot find a Pareto improvement. We present an example with arbitrarily small income effects in which no market equilibrium is minimally constrained efficient.Received: 26 November 2002, Revised: 28 May 2003, JEL Classification Numbers: D2, D52, D61, G1.We are grateful to an anonymous referee for very valuable comments. E. and H. Dierker would like to thank the Institute of Economics, University of Copenhagen, for its hospitality and its financial support.     

Regularity of pure strategy equilibrium points in a class of bargaining games

Summary. We develop an index theory for the Stationary Subgame Perfect (SSP) equilibrium set in a class of n-player sequential bargaining games with probabilistic recognition rules. For games with oligarchic voting rules (a class that includes unanimity rule), we establish conditions on individual utilities that ensure that for almost all discount factors, the number of SSP equilibria is odd and the equilibrium correspondence lower-hemicontinuous. For games with general, monotonic voting rules, we show generic (in discount factors) determinacy of SSP equilibria under the restriction that the agreement space is of dimension one. For non-oligarchic voting rules and agreement spaces of higher finite dimension, we establish generic determinacy for the subset of SSP equilibria in pure strategies. The analysis also extends to the case of fixed delay costs. Lastly, we provide a sufficient condition for uniqueness of SSP equilibrium in oligarchic games.Received: 13 May 2004, Revised: 1 March 2005, JEL Classification Numbers: C62, C72, C78.I thank John Duggan and participants of the 2003 annual meeting of the American Political Science Association, Philadelphia, PA, the Political Economy Seminar at Northwestern University, and the Economic Theory seminar at the University of Rochester for helpful comments.     

Computing equilibria in finance economies with incomplete markets and transaction costs

Summary. Transaction costs on financial markets may have important consequences for volumes of trade, asset pricing, and welfare. This paper introduces an algorithm for the computation of equilibria in the general equilibrium model with incomplete asset markets and transaction costs. We show that economies with transaction costs can be analyzed with differentiable homotopy techniques and thus in the same framework as frictionless economies despite the existence of non-differentiabilities of agents asset demand functions and the existence of locally non-unique equilibria. We introduce an equilibrium selection concept into the computation of economic equilibria that picks out a specific equilibrium in the presence of a continuum of equilibria.Received: 2 December 2002, Revised: 15 November 2004, JEL Classification Numbers: C61, C62, C63, C68, D52, D58, G11, G12. Correspondence to: P. Jean-Jacques HeringsThis research started when Jean-Jacques Herings enjoyed the generous hospitality of the Cowles Foundation for Research in Economics at Yale University. His research has been made possible by a fellowship of the Royal Netherlands Academy of Arts and Sciences and a grant of the Netherlands Organisation for Scientific Research. We thank audiences at Stanford University, UC San Diego, and Venice for discussions on the subject. We are very grateful to an anonymous referee for very helpful comments on an earlier draft.     

Price rigidities and institutional variations in markets with posted prices

Summary An exchange economy with price rigidities and rationing is considered. The rationing systems allowed are very general. Several characterizations of the set of constrained equilibria are given, and new equilibrium existence results are provided. More specifically, well-known properties like the existence of equilibria without rationing of the numeraire commodity, and the existence of supply and demand constrained equilibria without rationing on the market of at least one commodity follow as special cases from the theorems proved. Finally it is shown that the equilibrium correspondence is upper semi-continuous, while it is continuous on a residual set of points. In order to prove these results a new continuity result for the budget correspondence is given.The author would like to thank Dolf Talman, Gerard van der Laan, Jan van Geldrop, and an anonymous referee for their valuable comments on previous drafts of this paper. The author is financially supported by the Cooperation Centre Tilburg and Eindhoven Universities, The Netherlands. This research is part of the VF-program Competition and Cooperation.     

Work Incentives and Labor Supply Effects of the ‘Mini-Jobs Reform’ in Germany

We analyze the work incentives and labor supply effects of the so-called mini-jobs reform (subsidies of social security contributions to people with low-earnings jobs) introduced in Germany in April 2003. The analysis is based on a structural labor supply model embedded in a detailed tax-benefit microsimulation model for which we use the German Socio-Economic Panel (GSOEP). Our simulation results show that the likely employment effects of the mini-jobs reform will be small. The small positive participation effect is outweighed by a negative hours effect among already employed workers. The fiscal effects of the reform are also likely to be negative. We conclude that the analyzed mini-jobs reform is not an effective policy to increase employment of people with low earnings capacity.*We thank the German Science Foundation (DFG) for financial support under the research program Flexibilisierungspotenziale bei heterogenen Arbeitsmärkten (project STE 681/5-1).     

Perfect Bayesian implementation

Summary We study Social Choice Sets (SCS) implementable as perfect Bayesian equilibria of some incomplete information extensive form game. We provide a necessary condition which we callcondition . The condition is analogous tocondition C that Moore and Repullo [1988] show to be necessary for subgame perfect implementation in games of complete information, and it is weaker than the Bayesian Monotonicity condition stated in Jackson [1991]. Our first theorem establishes that Incentive Compatibility, Closure and Condition are necessary for implementation.Our second theorem establishes sufficient conditions. We show that any SCS which satisfies Incentive Compatibility, Closure and a condition called Sequential Monotonicity No Veto (SMNV) is implementable. SMNV is similar in spirit but weaker than the Monotonicity No Veto condition stated in Jackson [1991]. It is also similar to a combination of condition and No Veto Power, which Abreau and Sen show to be sufficient for implementation in subgame perfect equilibrium.This paper is a revised version of a chapter of my dissertation at Stanford University, Graduate School of Business. I would like to thank, without implicating, Faruk Gul, Bob Wilson and especially John Roberts for their constant advice and encouragement. I would also like to thank participants at the 1993 Summer Meeting of the Econometric Society and a referee for comments leading to substantial improvement in the paper. Financial support from Bocconi University is gratefully acknowledged.     

The overprovision anomaly of private public good supply

It is well known that private provision of a public good may lead to a higher supply than that in some Pareto optimal allocation. The traditional view attributes this overprovision anomaly to a specific kind of preferences. The present paper, however, shows that preferences do not play a decisive role. Assuming normality, overprovision will occur only if the distribution of income is extremely skewed and Pareto optimal allocations are not within the set of cost-share equilibria.     

Sunspots,indeterminacy and Pareto inefficiency in economies with incomplete markets

Summary. We consider two periods economies with both intrinsic and extrinsic uncertainty. Asset markets are incomplete in the certainty economy. If assets are nominal, there are enough commodities and the number of agents is greater than two and smaller than the total number of states of nature tomorrow (minus one), then a sunspot-invariant equilibrium is generically Pareto dominated by some sunspot equilibria. When assets are real, and there are enough commodities, if there are sunspot equilibria, there are sunspot equilibria Pareto dominating sunspot-invariant equilibria under the same restriction on the number of agents (and stronger restrictions on the number of commodities).Received: 20 October 2003, Revised: 1 April 2004, JEL Classification Numbers: D52.I wish to thank Paolo Siconolfi for helpful suggestions and comments. I aknowledge the financial support of M.I.U.R. and the kind hospitality of C.C.D.R. in Summer 2003.     

A note on repeated-offers bargaining with one-sided incomplete information

Summary This note analyzes a modified version of the standard repeated-offers bargaining game with one-sided incomplete information studied in Fudenberg, Levine and Tirole (1985), Gul, Sonnenschein and Wilson (1986) and Ausubel and Deneckere (1989). The modification, which is introduced in the extensive form, is that the (uninformed) seller can choose to withdraw her offer immediately after the (informed) buyer accepts it. This modification is important because it removes the (implicit) commitment assumption built into the standard model that the seller is committed not to withdraw her price offer. A main result obtained is, that whether or not there is a gap between the seller's valuation and the lowest possible buyer's valuation, any seller payoff between zero and the static monopoly profit can be supported by sequential equilibria. Thus, even in the gap case there exist equilibria that completely reverse the Coase conjecture.I thank Ian Jewitt and an anonymous referee for their helpful advice and comments.     

A note on conspicuous leisure,animal spirits and endogenous cycles

This paper investigates general equilibrium effects of conspicuous leisure. It finds that leisure externalities reduce the degree of other market imperfections needed to generate indeterminacy or sunspot equilibria - endogneous cycles become empirically more plausible. Sunspot equilibria are possible with a downward-sloping labor demand schedule. The economic reasoning behind the result is that with conspicuous-externalities, labor is drawn more easily in and out of leisure to help fulfill agents expectations.Received: June 2003, Accepted: January 2004, JEL Classification: E32Mark Weder: I thank Paulo Brito (the Editor), Michael Burda and an anonymous referee for very helpful comments and suggestions. All remaining errors are my own. Support by the Deutsche Forschungsgemeinschaft in the form of a Heisenberg Fellowshipis gratefully acknowledged.