RIEB, Kobe University - Kanematsu Seminar (January 10, 2012)

Kanematsu Seminar（Jointly supported by: Rokkodai Theory Seminar）

Date&Time	Friday, February 1, 2013, 1:20pm-
Place	Seminar Room at RIEB (Kanematsu Memorial Hall 1st Floor)
Intended Audience	Faculty, Graduate Students and People with Equivalent Knowledge
Language	Japanese
Note	Copies of the paper will be available at Office of Promoting Research Collaboration.

Speaker	Hirofumi YAMAMURA
Affiliation	Graduate School of Decision Science and Technilogy, Tokyo Institute of Technology
Topic	Coalitional Stability in the NIMBY Problem: An Application of the Mimimax Theorem
Abstract	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.

Speaker	Manabu TODA
Affiliation	Faculty of Social Sciences, Waseda University
Topic	Characterization of Stable Solutions in Matching Markets
Abstract	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).