Research Papers

Working Papers and Extended Versions of Published Papers

• "Assessment Aggregation under Conflict of Interest" (joint with Yoko Kawada, Komazawa U., Yuta Nakamura, Yokohama City U., and Noriaki Okamoto, Meiji Gakuin U.) (SSRN version as of 2026/03/27.) NEW!

• "Inspecting Cartels over Time: With and without Leniency Program" (joint with Yosuke Yasuda, GRIPS). (SSRN version as of 2026/03/26). Revised!

• "Evolutionary Instability of Cooperation towards Strangers in Voluntary Partnerships". 2025 Econometric Society World Congress paper, Abstract.  (Draft as of 2025/10/06) Updated!

• "Voluntary Partnerships and Cooperation: An Experimental Study" (joint with Naoko Nishimura, Ritsumeikan U., Masahiro Okuno-Fujiwara, U. Tokyo (emeritus), and Nobue Suzuki, Komazawa U.) August, 2023.  SSRN 4521316  

• "On the Folk Theorem in Self-Sustained Communities" (joint with Yosuke Yasuda, Osaka University). (draft as of 2022/01/24). 

• "Tolerance in Voluntary Partnerships" (joint with Masahiro Okuno-Fujiwara, emeritus professor, University of Tokyo) (draft as of 2021/08/19)  

Older drafts:

*"Accountable Voting" (joint with Yoko Kawada, Komazawa U., Yuta Nakamura, Yokohama City U., and Noriaki Okamoto, Meiji Gakuin U.) (draft as of 2025/03/18)  SSRN 4406802.  This is a focused version of the 2021 manuscript.  

*"Accountable Voting: Impossibility and an Analysis of Concrete Rules" (joint with Yoko Kawada, Komazawa U., Yuta Nakamura, Yokohama City U., and Noriaki Okamoto, Meiji Gakuin U.)  (Draft of 2021.) SSRN 3786674.

*"Exit Option can Make Cooperation Easier" (joint with Yosuke Yasuda, Osaka University) (Latest version as of 2017/12/12.)

*"Tolerance and Behavioral Diversity" (joint with Masahiro Okuno-Fujiwara, University of Tokyo emeritus) (Latest version as of 2019/1/2.)

Older versions have the title:  "Diverse Behavior Patterns in a Symmetric Society with Voluntary Partnerships" ( Old version as of 2016/10/14.  SSRN version.)

*"Dynamic Noncooperative Group Formation with Size Advantage and Group Reputation" (Latest version as of 2015/08/08.)

*"Inspecting Cartels" (joint with Yosuke Yasuda, Osaka University) (An old version as of July 2014)

Recently (?) Published Papers

The complete list of my work is available in my cv at Keio University.

*"Repeated games with partner choice" (joint with Christopher Graser, Julian Garcia, and Matthijs van Veelen). PLOS Computational Biology, 2025, 21(2): e 1012810. NEW!

*"Farsighted Clustering with Group-Size Effects and Reputations" (joint with Toru Hokari, Keio University).  Dynamic Games and Applications,  2023, 13, 610-635. (Submitted version of 2022/07/26.  Online Appendix.)  

*"Algorithms may not learn to play a unique Nash equilibrium" (joint with Carsten Krabbe Nielsen,  Catholic University of Milan.) Journal of Computational Social Science,  2021, 4(2), 839-850.  (Final version.  2021/02/14.)  

* "Asymmetry of Customer Loss and Recovery under Endogenous Partnerships: Theory and Evidence" (joint with Henrich R. Greve, INSEAD, and Stefan Jonsson, Uppsala University) International Economic Review, 2016, 57(1), 3-30.    (Extended version pdf file.)

*"Efficiency may Improve when Defectors Exist" (joint with Masahiro Okuno-Fujiwara, Musashino University, and Nobue Suzuki, Komazawa University)  Economic Theory, 2015, 60(3), 423-460.