Manipulation of the Walrasian mechanism in production economies with unbounded short-selling

Hurwicz (1979) and Otani and Sicilian (1982, 1990) characterized the Nash equilibrium allocations of the Walrasian demand manipulation game in successively more general exchange environments. In this paper, I extend the analysis to production economies with short-selling. First, I generalize Hurwicz’s and Otani and Sicilian’s theorem that any allocation at which each agent’s consumption bundle lies above her true offer curve can be supported in Nash equilibrium. I then show that for finite economies of any size the set of such allocations is often topologically large.Received: 17 January 2003, Accepted: 4 April 2005, JEL Classification: D51, D82For comments on this and earlier versions of the paper, I wish to thank Rick Bond, Bhaskar Chakravorti, Tom Gresik, Costas Syropoulos and William Thomson. I would especially like to thank Mike Jerison for helping to overcome a difficulty with a previous version. Also, the comments of the anonymous referees are gratefully acknowledged.     

Nash implementation with an infinite-dimensional trade space

This paper deals with the problem of implementing the Walras correspondence via Nash equilibria, in exchange economies with infinitely many commodities and finitely many households with possibly non-ordered preferences. We explicitly construct a feasible mechanism enjoying some features, which have natural economic meanings. Under a fairly weak boundary condition, this game fully implements the Walras equilibria. If this condition is not fulfilled, our mechanism nevertheless implements the constrained Walras equilibria. Received: 11 December 2003, Accepted: 29 July 2005 JEL Classification: D41, D43, D51 We thank (without implicating) Prof. Jean-Marc Bonnisseau and Cuong Le Van for helpful comments. The views expressed in this paper reflect those of the authors and not necessarily those of Calyon.     

A free-rider problem with a free-riding principal

In a moral hazard problem caused purely by joint production and not by uncertainty, we examine the problem faced by a principal who actively participates in production along with a group of agents. We show that, when designing the optimal output sharing rule, the principal need not look for anything more complicated than the frequently observed simple linear or piecewise linear rules. We also confirm the presence of a friction between the principal’s residual claimant role and her incentive to free-ride in the production process that prohibits her from completely mitigating the moral hazard problem. This paper is from the first chapter of my Ph.D. dissertation at The University of British Columbia, Canada, 1993. I would like to thank my thesis supervisor John Weymark for his many helpful comments and suggestions. I have also benefitted from the comments of Charles Blackorby, David Donaldson, Mukesh Eswaran, Kenneth Hendricks, Ashok Kotwal and Guofu Tan. An anonymous referee and an associate editor provided helpful suggestion. I am also grateful for the hospitality of the Indian Statistical Institute, Delhi Centre, and the Centre for Development Economics, Delhi School of Economics, where parts of the paper were revised while I was a visitor. I am solely responsible for any remaining errors and omissions.     

Stable matchings and the small core in Nash equilibrium in the college admissions problem

Both rematching proof and strong equilibrium outcomes are stable with respect to the true preferences in the marriage problem. We show that not all rematching proof or strong equilibrium outcomes are stable in the college admissions problem. But we show that both rematching proof and strong equilibrium outcomes in truncations at the match point are all stable in the college admissions problem. Further, all true stable matchings can be achieved in both rematching proof and strong equilibrium in truncations at the match point. We show that any Nash equilibrium in truncations admits one and only one matching, stable or not. Therefore, the core at a Nash equilibrium in truncations must be small. But examples exist such that the set of stable matchings with respect to a Nash equilibrium may contain more than one matching. Nevertheless, each Nash equilibrium can only admit at most one true stable matching. If, indeed, there is a true stable matching at a Nash equilibrium, then the only possible equilibrium outcome will be the true stable matching, no matter how different are players' equilibrium strategies from the true preferences and how many other unstable matchings are there at that Nash equilibrium. Thus, we show that a necessary and sufficient condition for the stable matching rule to be implemented in a subset of Nash equilibria by the direct revelation game induced by a stable mechanism is that every Nash equilibrium profile in that subset admits one and only one true stable matching. Received: 30 December 1998 / Accepted: 12 October 2001 This paper is a revision of the paper “Manipulation and Stability in a College Admissions Problem” circulated since 1994. I thank Rich McLean, Abraham Neyman, Mark Satterthwaite, Sang-Chul Suh, and Tetsuji Yamada for helpful discussions. I thank the associate editor and the two anonymous referees for their helpful comments that have greatly improved the paper. I am grateful to the Kellogg G.S.M. at the Northwestern University for the hospitality for my visit. Any errors are mine.     

Integral stochastic optimal design criteria in linear models

Within the framework of classical linear regression model integral optimal design criteria of stochastic nature are considered and their properties are established. Their limit behaviour generalizes that of the distance stochastic optimality criterion. As an example a line fit model is taken. Acknowledgement. I would like to thank the referees for their constructive comments which improved the paper.     

Optimal procurement mechanisms for divisible goods with capacitated suppliers

Procurement auction literature typically assumes that the suppliers are uncapacitated [see, e.g. Dasgupta and Spulber in Inf Econ Policy 4:5–29, 1990 and Che in Rand J Econ 24(4):668–680, 1993]. Consequently, the auction mechanisms award the contract to a single supplier. We study mechanism design in a model where suppliers have limited production capacity, and both the marginal costs and the production capacities are private information. We provide a closed-form solution for the revenue maximizing direct mechanism when the distribution of the cost and production capacities satisfies a modified regularity condition [Myerson in Math Oper Res 6(1):58–73, 1981]. We also present a sealed low bid implementation of the optimal direct mechanism for the special case of identical suppliers. The results in this paper extend to other principle-agent mechanism design problems where the agents have a privately known upper bound on allocation. The authors would like to thank the anonymous referees for valuable suggestions and comments.     

Mechanism design for a solution to the tragedy of commons

We consider the problem of the tragedy of commons in cooperative production economies, and propose a mechanism to resolve this tragedy, taking into account that the coordinator cannot perfectly monitor each agent’s labor skill and each agent may have an incentive to overstate as well as understate his own skill. Even in such a situation, the mechanism implements the proportional solution (Roemer in Soc Philos Policy 6:74–92, 1989 and Roemer and Silvestre in J Econ Theory 59:426–444, 1993) in Nash and strong equilibria when it is played as a normal form game. Moreover, the mechanism triply implements the solution in Nash, subgame-perfect, and strong equilibria when it is played as a two-stage extensive form game. We are greatly thankful to Semi Koray, William Thomson, and an anonymous referee of this journal for their concrete and helpful comments on improving the paper. An earlier version of this paper was presented at the annual meeting of the Japanese Economic Association held at Hitotsubashi University in October 2001 and at the Conference on Economic Design held at NYU in July 2002. We are grateful to Takehiko Yamato for his useful comments in the former conference. We are also thankful to Tatsuyoshi Saijo, Kotaro Suzumura, and Yoshikatsu Tatamitani for their kind comments.     

Spatial social networks

We introduce a spatial cost topology in the network formation model analyzed by Jackson and Wolinsky, Journal of Economic Theory (1996), 71: 44–74. This cost topology might represent geographical, social, or individual differences. It describes variable costs of establishing social network connections. Participants form links based on a cost-benefit analysis. We examine the pairwise stable networks within this spatial environment. Incentives vary enough to show a rich pattern of emerging behavior. We also investigate the subgame perfect implementation of pairwise stable and efficient networks. We construct a multistage extensive form game that describes the formation of links in our spatial environment. Finally, we identify the conditions under which the subgame perfect Nash equilibria of these network formation games are stable. We are very grateful for the constructive comments of Matt Jackson and an anonymous referee. We also like to thank Vince Crawford, Marco Slikker, Edward Droste, Hans Haller, Dimitrios Diamantaras, and Sudipta Sarangi for comments on previous drafts of this paper.We acknowledge Jay Hogan for his programming support. Part of this research was done while visiting the CentER for Economic Research, Tilburg University, Tilburg, The Netherlands.Financial support from the Netherlands Organization for Scientific Resrarch (NWO), grant B46-390, is gratefully acknowledged.-->,     

Repeated implementation and complexity considerations

A game form is commitment-free if single actions of players do not have physical consequences, i.e., affect the continuation game. Such game can be thought to represent inifinite interaction with complete patience. A choice rule can be Nash implemented via a commitment-free mechanism if and only if it coincides with the feasible set of a normal form game. However, when players are complexity averse (in the lexicographic sense), then any Nash implementable choice rule becomes available. I am very grateful to Matt Jackson and a referee for their comments. I also thank Klaus Kultti and Hannu Salonen for useful conversations.     

Implementing efficient market structure

Abstract. This article studies the design of optimal mechanisms to regulate entry in natural oligopoly markets, assuming the regulator is unable to control the behavior of firms once they are in the market. We adapt the Clarke–Groves mechanism, characterize the optimal mechanism that maximizes the weighted sum of expected social surplus and expected tax revenue, and show that these mechanisms avoid budget deficits and prevent excessive entry. Received: 7 May 2001 / Accepted: 24 June 2002 We would like to thank seminar participants at Bonn and Berlin, in particular Peter Bank, Wieland Müller, and Urs Schweizer, the two anonymous referees, and the associate editor for most useful and exceptionally detailed comments. Financial support was received by the Deutsche Forschungsgemeinschaft, SFB 373 (“Quantifikation und Simulation ?konomischer Prozesse”), Humboldt–Universit?t zu Berlin.     

The theory of contests: a survey

This paper presents a survey of the theory of contests. This paper is an outgrowth of lecture notes of Ph.D. courses given in Carlos III University, Universitat Autònoma de Barcelona and Universidad de Málaga. I would especially like to thank to Carmen Beviá for her comments and suggestions and Matthias Dahm for allowing me free access to a joint paper and for correcting many mistakes and very helpful suggestions. I also thank Clara Eugenia García, Cristian Litan, Carlos Pimienta, Santiago Sánchez-Pages, Ramon Torregrosa, Galina Zudenkova and the students of this course for their helpful comments and CAICYT for research grant SEJ2005-06167/ECON.     

Proportionally adjusted marginal pricing method to share joint costs

We consider the cost sharing problem with divisible demands of heterogeneous goods. We propose a cost sharing method called Proportionally Adjusted Marginal Pricing (PAMP) method. PAMP is a nonadditive (in the cost function) extension of average cost pricing. We introduce an axiom called Local Independence (LI) and use LI together with Continuity, Proportionality, and Scale Invariance to characterize PAMP. Received: 23 March 2001 / Accepted: 16 November 2001 I thank Yves Sprumont, Hervé Moulin, and Ahmet Alkan for discussions, comments and suggestions. Thanks also go to the associate editor and the referees, whose comments and suggestions greatly improve the paper.     

Black’s hypothesis and developed economies

This paper examines the relationship between the volatility of output growth and the average growth rate of output in developed economies using the Generalized Auto-Regressive Conditional Hetereoskedasticity-in-mean (GARCHM) framework. The results indicate that that volatility is correlated with output growth for half of the countries and that the correlation is negative for some countries and positive for others. This finding is consistent with models that suggest country characteristics are important for determining the growth-volatility ralationship. However, the estimated correlation between volatility and the average growth rate is sensitive to the specification of the conditional variance equation. I would like to thank Donn Johnson for his helpful comments on an earlier version of this paper.     

Implementation of social optimum in oligopoly

This paper presents a decentralized mechanism implementing socially optimal output choices by non-cooperatively acting oligopolists. A decentralized mechanism is a vector of balanced transfers among firms determined as a function of firms’ output choices. The mechanism is devised by a regulator with a full knowledge of demand and without any knowledge of the firms’ cost functions. Restricting the set of admissible demand and cost functions such that the firms always have an incentive to produce, it turns out that the socially optimal solution is implementable insofar as the demand function is a polynomial of at most (n−1)th degree, n being the number of firms in the industry. The author is indebted to a referee and an associate editor for their helpful comments.     

Equilibrium allocations of endowment-pretension games in public good economies

In a public good economy where agents' preferences are known but endowments are private information, instituting an allocation rule and asking the agents their initial endowments induces an endowment-pretension game. We analyse the Nash equilibrium allocations of this game and discuss its welfare properties with reference to voluntary contributions allocations. Received: 30 May 2001, Accepted: 23 September 2005 JEL Classification: H41 I am grateful to Murat Sertel for his continuous support and encouragement; to G?ksel Asan and Arunava Sen for their invaluable help. I would also like to thank Fikret Adaman, Ahmet Alkan, Salvador Barberá, Semih Koray, Andrei Ratiu, Muhamet Yíldíz, ünal Zenginobuz, an Associate Editor and two referees of the Review of Economic Design for their enlightening comments on previous drafts. Earlier versions of this paper were written during my stay at Universitat Autónoma de Barcelona and at the Indian Statistical Institute. Both visits have been possible by the kindness of the host institutions and the financial support of the Turkish Academy of Sciences and Serem Ltd. It is a pleasure for me to express my gratitude to all these institutions. Of course, all possible errors are mine.     

Characterizing neutrality in the voluntary contribution mechanism

When public goods are provided by voluntary contributions, redistribution of initial holdings among an unchanged set of contributors will not alter the Nash equilibrium allocation.Constraint invariance, where a participant faces the same class of constraints even after her endowment is changed, impliesglobal neutrality under a generalized Nash equilibrium concept. Geometrically,path invariance, where the best response path does not move even after the endowment change, is equivalent to global neutrality assuming a sufficiently rich class of economies. We thank Shinji Ohseto, Hiroaki Osana and Stephen Turnbull for their comments. We are also grateful to an anonymous referee and an associate editor for their comments and suggestion. Research was partially supported by the Nomura Foundation for the Social Sciences and the Grant in Aid for General Research 03803008 of the Ministry of Education, Science and Culture of Japan.     

Reducing informational costs in endowment mechanisms

We consider the problem of designing an economic mechanism for reallocation of endowments. In this class of economic environments, an additional restriction can be imposed which prevents agents from overstating their endowments. We explore the extent to which the additional information gained from no overstatement can be used to reduce the informational cost of an endowment mechanism. The ideas are also extended to production environments. We would like to thank Leo Hurwicz, Stanley Reiter, Matthew Jackson, Thomas Palfrey and Yan Chen for helpful comments and suggestions.     

A channel model of investment decision: An intertemporal planning approach

The paper considers some theoretical implications of the Oslo-Cairo intertemporal planning model (the channel model). A version of the channel model with private and public investment projects is developed. The optimality properties of the model are derived. It is shown that: (i) Pareto solution can be supported by competitive prices and (ii) a ranking criterion can be constructed in the spirit of cost-and-benefit analysis. The results brings the channel model theoretically in line with the classical resource allocation models.This paper is a revised and abridged version of Chapter Two of my doctoral dissertation at the University of Kansas. I wish to thank Professor Mohamed El-Hodiri, Chairman of my thesis committee, for his guidance and support and for introducing me to the theory of optimal control with delays. I would also like to thank Professors Van Vleck, Paul Comolli, David Burress and Tom Weiss for their helpful suggestions. The paper has benefited substantially from the comments provided by anonymous referees. I remain responsible for all errors and inaccuracies.     

Social identity,inequality, and conflict: correction and extension

This paper corrects and extends the analysis in Social Identity, Inequality, and Conflict by James Robinson (Economics of Governance, 2(1), 2001). For conflict along class lines, Robinson finds the total impact of mobility on conflict to be ambiguous. Contrary to his result, I show that, under his assumptions, the effect of social mobility on class conflict is unambiguous. Higher mobility always decreases conflict. In my extension to Robinsons model, I explore mobilitys impact on class conflict in a society where the tax rate is not fixed. I demonstrate that if the tax rate is proportional to the population of the group in power relative to the total population of the society, then the effects of social mobility on class conflict are indeed ambiguous.Submitted: February 2002, Accepted: July 2003,I am grateful to an anonymous referee and Amihai Glazer for their comments. I would also like to thank Herschel Grossman for his help along the way.     

Implementation of the Walrasian correspondence by market games

Abstract. In this paper we present a set of axioms guaranteeing that, in exchange economies with or without indivisible goods, the set of Nash, Strong and active Walrasian Equilibria all coincide in the framework of market games. Received: 25 December 1998 / Accepted: 8 April 2002 We are very grateful to William Thomson for many suggestions. Also we would like to thank comments from J. Alcalde, R. Bhattacharya, C. Herrero, P. Marhuenda, D. Pérez-Castrillo, A. Romero-Medina, T. Shinotsuka, T. Sj?str?m, and A. Villar, an associated editor and an anonymous referee. The first author thanks financial support from DGCYT and Direcció General de Reserca under projects PB98-0870, and SGR2000-00054. The second author wishes to acknowledge financial help from DGCYT under project PB98-0940.