兼松セミナー（六甲台セオリーセミナー共催）Kanematsu Seminar（Jointly supported by: Rokkodai Theory Seminar）

日時 2013年2月1日（金）午後1時20分から
会場 神戸大学経済経営研究所　調査室（兼松記念館1階）
対象 教員、院生、および同等の知識をお持ちの方
使用言語 日本語
備考 論文のコピーは共同研究推進室にご用意いたします。

1:20pm～2:50pm

報告者 山邑　紘史
所属 東京工業大学大学院社会理工学研究科
論題 Coalitional Stability in the NIMBY Problem: An Application of the Mimimax Theorem
概要 We consider the situation in which agents choose the location of a public bad from a street according to a given voting mechanism. We study coalitional behaviors in such a situation. We identify a necessary and sufficient condition for a voting mechanism to possess a strong Nash equilibrium by applying the minimax theorem (von Neumann and Morgenstern, 1944). We moreover characterize the class of solutions that can be implemented in strong Nash equilibria. As a by-product of these results, we propose a simple voting mechanism that implements any solution that can be implemented in strong equilibria.

3:10pm～4:40pm

報告者 戸田　学
所属 早稲田大学社会科学総合学術院
論題 Characterization of Stable Solutions in Matching Markets
概要 In the setting of two-sided matchings, we propose a new consistency axiom based on the idea of Davis and Maschler (1965). Given an agreement between agents, a proper subset of agents are going to renegotiate within themselves. Then, it becomes relevant what each agent can obtain from the outside of the group. Following the idea of Davis and Maschler, we assume that they expect to obtain the "maximum" from the outside agents as long as the current outcome is guranteed. Our new consistency axiom requires the current outcome being at least as good as the maximum. It is easy to show that any stable solution is consistent and any consistent solution is stable. This is closely related to the characterization of the stable solution obtained by Adachi (2000).

We also obtain characterizations of the core, the whole set of stable outcomes, as well as a characterization of the deferred acceptance rule, which is comparable with the recent results of Kojima and Manea (2009).