game theory, social choice
 Complexity consideration on the existence of strategy-proof social choice functions. (2010)
(Revised version 2010/07/13)
 Maskin monotonic coalition formation rules respecting group rights. (2008)
(revised version 2010/01/07)
 Consistency and Unanimity in the House Allocation Problem I: Collective Initial Endowments. (2006)
(revised version 28 April 2006)
 Mutual Knowledge of Rationality in the Electronic Mail Game. (2004) (with Akira Tanaka)
Articles published/to be published
 Computational complexity in the design of voting rules. (with Akira Tanaka)
Theory and Decision
80(1) (Jan 2016) pp.33--41,
 Coalitional unanimity versus strategy-proofness in coalition formation problems.
International Journal of Game Theory
42(1) (Feb 2013) pp.115--130,
 Preference Revelation Games and Strong Cores of Allocation Problems with Indivisibilities.
Journal of Mathematical Economics 45(1,2) (Jan 2009) pp.199--204.
 Domains of Social Choice Functions on Which
Coalition Strategy-proofness and Maskin Monotonicity Are Equivalent.
Economics Letters 95(3) (June 2007) pp.348--54.
The published version contains some typos. I recommend referring to the original manuscript posted here.
 On the Equivalence of G-weak and -strong Cores in the Marriage Problem.
Economics Bulletin 3(19) (Aug 31, 2006) pp1--8.
 The Weak Core of Simple Games with Ordinal Preferences: Implementation in Nash Equilibrium.
(with Tomoichi Shinotsuka)
Games and Economic Behavior 44(2) (Aug 2003) pp379-89.
This paper contains some errors. We have corrected them only recently. (2013/06)
 On Strategy-Proofness and Essentially Single-Valued Cores: A Converse Result.
Social Choice and Welfare 20(1) (Jan 2003) pp77-83.
 The Consistency Principle and an Axiomatization of the alpha-Core.
International Journal of Game Theory vol 30(2) (Dec 2001) pp195-207.
 Coalition Strategy-Proofness and Monotonicity in Shapley-Scarf Housing Markets.
Mathematical Social Sciences vol 41(2)(March 2001) pp201-13.
 A Basic Lemma on Social Welfare Functions: Derivation of Arrow's and Sen's Theorems.
Economic Journal of Hokkaido University vol 29(July 2000) pp121-7.