記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER HEIDELBERG  

Groves and Ledyard (Econometrica 45:783-809, 1977) constructed a mechanism attaining Pareto efficient allocations in the presence of public goods. After this path-breaking paper, many mechanisms have been proposed to attain desirable allocations with public goods. Thus, economists have thought that the free-rider problem is solved, in theory. Our view to this problem is not so optimistic. Rather, we propose fundamental impossibility theorems with public goods. In the previous mechanism design, it was implicitly assumed that every agent must participate in the mechanism that the designer provides. This approach neglects one of the basic features of public goods: non-excludability. We explicitly incorporate non-excludability and then show that it is impossible to construct a mechanism in which every agent has an incentive to participate.

DOI： 10.1007/s10058-009-0100-0

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We study a general class of pure exchange economies that have multiple equilibria. This class generalizes an example presented by Shapley and Shubik. For such economies, we find easily verified conditions that determine whether there are multiple equilibria. We also provide simple methods for constructing economies in which arbitrary pre-specified sets of prices are equilibria. These economies have strong comparative statics properties, since prices at interior competitive equilibrium depend on the parameters of utility but not on the endowment quantities. We believe that this easily manipulated special case is a valuable addition to the class of simple general equilibrium economies that can be used as testing grounds in economic theory. © 2009 The Berkeley Electronic Press. All rights reserved.

DOI： 10.2202/1935-1704.1609

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

In this paper, we examine which auction format, first-price or second-price, a seller will choose when he can profitably cheat in a second price auction by observing all bids by possible buyers and submitting a shill bid as pretending to be a buyer. We model this choice of auction format in seller cheating as a signaling game in which the buyers may regard the selection of a second price auction by the seller as a signal that he is a shill bidder. By introducing trembling-hand perfectness as a refinement of signaling equilibrium, we find two possible strictly perfect signaling equilibria. One is a separating equilibrium in which a noncheating honest seller selects a first price auction and a cheating seller does a second price auction. In another pooling equilibrium, however, both cheating and non-cheating sellers select a second price auction. The conclusion that a seller chooses a second price auction even if he cannot cheat is in contrast to the previous literature, which focused on the case of independent values.

DOI： 10.1007/s00199-007-0262-3

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掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ECONOMETRIC SOCIETY  

Strategy-proofness, requiring that truth-telling be a dominant strategy, is a standard concept in social choice theory. However, this concept has serious drawbacks. In particular, many strategy-proof mechanisms have multiple Nash equilibria, some of which produce the wrong outcome. A possible solution to this problem is to require double implementation in Nash equilibrium and in dominant strategies, i.e., secure implementation. We characterize securely implementable social choice functions and investigate the connections with dominant strategy implementation and robust implementation. We show that in standard quasi-linear environments with divisible private or public goods, there exist surplus-maximizing (non-dictatorial) social choice functions that can be securely implemented.

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記述言語：日本語   出版者・発行元：岩波書店  

真の選好表明が支配戦略であることを要求する戦略的操作不能性は，社会選択理論において重要な概念として多くの研究がなされてきた．しかしながら，この概念は重大な欠陥を持っている．特に，ほとんどの戦略的操作不能なメカニズムには，たくさんのナッシュ均衡が存在し，悪い均衡結果を導きうる．この問題に対する一つの解決方法は，支配戦略均衡とナッシュ均衡での両方における二重遂行，すなわちセキュア遂行を要求することである．二つの戦略的操作不能なメカニズムに関する実験を行った．一つのメカニズムはセキュアではなく，多くの悪いナッシュ均衡を持ち，他のメカニズムはセキュアで，唯一の良いナッシュ均衡を持つ．被験者が支配戦略をとる比率は，セキュアでないメカニズムの方が，セキュアなメカニズムよりも有意に低いことを観察した．Strategy-proofness, requiring that truth-telling be a dominant strategy, is a standard concept used in social choice theory. However, we argue that this concept has serious drawbacks. In particular, many strategy-proof mechanisms have a continuum of Nash equilibria, some of which produce the wrong outcome. A possible solution to this problem is to require double implementation in dominant strategy equilibria and in Nash equilibria, called secure implementation. We conducted experiments on two strategy-proof mechanisms. One of them is not secure with many bad Nash equilibria, whereas the other secure mechanism has a unique good Nash equilibrium. We observed subjects adopted dominant strategies significantly less often in the non-secure mechanism than in the secure mechanism.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE  

Strategy-proofness, requiring that truth-telling is a dominant strategy, is a standard concept used in social choice theory. Saijo, Sjostrom and Yamato [Saijo, T., Sjostrom, T., Yamato, T., 2003. Secure implementation: Strategy-proof mechanisms reconsidered. Working paper 4-03-1. Department of Economics, Pennsylvania State University] argue that this concept has serious drawbacks. In particular, many strategy-proof mechanisms have a continuum of Nash equilibria, including equilibria other than dominant strategy equilibria. For only a subset of strategy-proof mechanisms do the set of Nash equilibria and the set of dominant strategy equilibria coincide. For example, this double coincidence occurs in the Groves mechanism when preferences are single-peaked. We report experiments using two strategy-proof mechanisms. One of them has a large number of Nash equilibria, but the other has a unique Nash equilibrium. We found clear differences in the rate of dominant strategy play between the two. (c) 2006 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.geb.2005.12.007

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© 2006, Birkhauser. In this paper, we examine the uniqueness of a reduced game in an axiomatic characterization of the core of transferable utility (TU) games in terms of consistency. Tadenuma [10] establishes that the core is the only solution satisfying non-emptiness, individual rationality, and consistency with respect to a natural reduced game due to Moulin [6]. However, the core satisfies consistency with respect to many other reduced games, including unnatural ones. Then we ask whether there are other reduced games that can be used to characterize the core based on the same three axioms. The answer is no: the Moulin reduced game is the only reduced game such that the core is characterized by the three axioms, since for any other reduced game, there is a solution that satisfies the three axioms, but it differs from the core. Many other unnatural reduced games cannot be used to characterize the core based on the three axioms. Funaki [4] provides another axiomatization of the core: the core is the only solution satisfying non-emptiness, Pareto optimality, sub-grand rationality, and consistency with respect to a simple reduced game similar to a so-called subgame. We show that the simple reduced game is the only reduced game that can be used to characterize the core by the four axioms.

DOI： 10.1007/0-8176-4501-2_8

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記述言語：日本語   出版者・発行元：滋賀大学  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE  

We conduct a two-stage game experiment with a non-excludable public good. In the first stage, two subjects choose simultaneously whether or not they commit to contributing nothing to provide a pure public good. In the second stage, knowing the other subject's commitment decision, subjects who did not commit in the first stage choose contributions to the public good. We found no support for the evolutionary stable strategy equilibrium, and the ratio of subjects who did not commit to contributing nothing increased as periods advanced; that is, the free-riding rate declined over time. Furthermore, this behavior did not arise due to altruism or kindness among subjects, but from spiteful behavior of subjects. (C) 2004 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.geb.2003.11.002

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記述言語：日本語  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

This paper studies voluntary public good provision in the laboratory, in a cross-cultural experiment conducted in the United States and Japan. Our environment differs from the standard voluntary contribution mechanism because subjects first decide whether or not to participate in providing this non-excludable public good. This participation decision is conveyed to the other subject prior to the subjects' contribution decisions. We find that only the American data are consistent with the evolutionary-stable-strategy Nash equilibrium predictions, and that behavior is significantly different across countries. Japanese subjects are more likely to act spitefully in the early periods of the experiment, even though our design changes subject pairings each period so that no two subjects ever interact twice. Surprisingly, this spiteful behavior eventually leads to more efficient public good contributions for Japanese subjects than for American subjects.

DOI： 10.1023/A:1020317321607

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記述言語：日本語  

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DOI： 10.1142/S0219198901000361

DOI： 10.1142/s0219198901000361

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記述言語：日本語   出版者・発行元：エネルギー・資源学会  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC  

We characterize natural implementability in exchange economies when a social choice correspondence possibly recommends a Pareto efficient allocation where the common marginal rate of substitution is not determined uniquely. We find that the no-envy and efficient (or fair) correspondence cannot be implemented by any natural mechanism with a price and a quantity announcement, but can be implemented by a natural mechanism with a price and two-quantity announcement. On the other hand, the constrained Walrasian correspondence can be implemented by a natural price-quantity mechanism with budget balance. Journal of Economic Literature Classification Numbers: C72, D51, D63, D78. (C) 1999 Academic Press.

DOI： 10.1006/game.1998.0703

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PHYSICA VERLAG GMBH  

In this paper we consider a model of an economy with a common pool resource. Under decreasing returns to scale, it is well-known that no Nash equilibrium attains Pareto efficiency. We examine whether it is possible to achieve Pareto efficiency and avoid the tragedy of the commons through cooperation among players. For that purpose, we use the notion of a game in partition function form. Whether or not the core exists depends crucially on the expectations of each coalition regarding the coalition formation of the outsiders. If each coalition has pessimistic expectations, then the core always exists, while if it has optimistic expectations, the core may be empty.

DOI： 10.1007/s001820050010

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Academic Press Inc.  

In the previous mechanism design on public goods, it was implicitly assumed that every agent must participate in the mechanism that the designer provides. This approach neglects non-excludability of public goods. We explicitly incorporate non-excludability and examine a two-stage game with voluntary participation: In the first stage, each agent simultaneously decides whether she participates in the mechanism or not, and in the second stage, knowing the other agents' participation decisions, the agents who selected participation in the first stage choose their strategies. Participation of all agents is not an equilibrium in many situations. Journal of Economic Literature Classification Numbers: C72, D71, D78, H41. © 1999 Academic Press.

DOI： 10.1006/jeth.1998.2476

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

This paper contains a full characterization of doubly implementable social choice correspondences (SCC's) in Nash equilibria and undominated Nash equilibria in general environments. We show that in the case of at least three agents, an SCC is doubly implementable if and only if it is Nash implementable. By contrast, for the case of two agents, the class doubly implementable SCC's is strictly smaller than that of Nash implementable SCC's. Nonetheless, the equivalence of Nash implementability and double implementability does hold in general environments for any SCC F satisfying a unanimity condition and the mild requirement that for each agent, no F-optimal alternative be worst. We give examples of interesting SCC's that are both Nash implementable and doubly implementable in economic environments.

DOI： 10.1016/S0304-4068(97)00054-2

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記述言語：日本語   出版者・発行元：慶應義塾大学  

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記述言語：英語   出版者・発行元：学術雑誌目次速報データベース由来  

We identify some fundamental conditions that a "natural" mechanism should satisfy in exchange economies. First, we provide necessary and sufficient conditions for social choice correspondences (SCCs) to be implemented in Nash equilibria by natural mechanisms. Second, we show that the class of SCCs implementable by (price and) two-quantity mechanisms is equivalent to the class of SCCs implementable by (price and) allocation mechanisms. Third, we find that the no-envy correspondence is implementable by a two-quantity mechanism, and the fair correspondence is implementable by a price-quantity mechanism.

DOI： 10.2307/2527318

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In addition to the natural requirements in mechanism design proposed by Saijo, Tatamitani, and Yamato (1995a), we introduce the simple punishment condition that requires the same feasible punishment whenever all participants simultaneously become potential deviators. First, we fully characterize the class of social choice correspondences (SCC's) implementable by price-quantity mechanisms with simple punishments. Second, we show that the no-envy and efficient correspondence cannot be implemented naturally with the simple punishment condition. Finally, the Walrasian correspondence and the individually rational and efficient correspondence are naturally implementable by using the initial endowment as a simple punishment in the case of at least three participants.

DOI： 10.1111/j.1468-5876.1996.tb00042.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER VERLAG  

This paper is concerned with the design of robust mechanisms which are applicable to a wide class of possible information structures of agents. We examine a society consisting of several groups such that (i) there are at least three agents in each group; and (ii) each agent knows the preferences of the agents in his group but has incomplete information about the preferences of the agents outside his group. We show that for a large class of information structures, a social choice set (SCS) is implementable for each possible information structure if and only if it is Nash implementable. In other words, the class of robustly implementable SCS's is identical to the class of implementable SCS's in the complete information setting.

DOI： 10.1007/BF00183299

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

This paper studies the issue of designing mechanisms that are applicable to a wide class of individual behavior in exchange economies with both “goods” and “bads.” We propose a mechanism such that for each possible preference profile, both the set of Nash equilibrium allocations and the set of undominated Nash equilibrium allocations coincide with the set of allocations that are optimal according to some social choice correspondence (SCC). Such a mechanism is said to “doubly” implement the SCC in Nash equilibria and undominated Nash equilibria. We show that in a large class of economies with ar least three agents, Maskin’s [Nash equilibrium and welfare optimality, mimeo, M.I.T., 1977] condition of monotonicity is necessary and sufficient for double implementation. Journal of Economic Literature Classification Numbers: C72, D51, D78. © 1993 Academic Press, Inc.

DOI： 10.1006/jeth.1993.1020

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In this paper, we extend Danilov's conditions for Nash implementation to weak preferences over an arbitrary set of alternatives. We show that a certain condition of "strong monotonicity" is necessary for Nash implementation if the domain of preferences is sufficiently large. Furthermore, in any preference domain of weak orders, it is also sufficient for Nash implementation if there are at least three agents. © 1992.

DOI： 10.1016/0899-8256(92)90051-S

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：学術雑誌目次速報データベース由来  

This paper deals with the welfare implications of information sharing between Bertrandtype duopolists when there is cost uncertainty. The paper distinguishes itself from the previous work in that it is not restricted to those special cases where goods are physically substitutes or costs are stochastically independent, and in that it carries out a complete analysis of the impact of information pooling on consumers and the society as a whole. In particular, by introducing new concepts such as the variation and allocation effects, we point out the possibility that the exchange of cost information is beneficial to Bertrand firms. Comparison with the more popular Cournot duopoly case is also made.

DOI： 10.11398/economics1986.41.48

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その他リンク： https://jlc.jst.go.jp/DN/JALC/10022433298?from=CiNii

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER-VERLAG WIEN  

DOI： 10.1007/BF01227870

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