Updated on 2024/04/28

写真a

 
OHTA,Katsunori
 
Organization
Faculty of Informatics Professor
Title
Professor
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Degree

  • 博士(経済学) ( 2005.3   神戸大学 )

Research Interests

  • Microeconomics

  • Game Theory

Research Areas

  • Humanities & Social Sciences / Economic theory

Education

  • Kobe University   Graduate School of Economics   Doctor Course

    2002.4 - 2005.3

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  • Kobe University   Graduate School of Economics   Master Course

    2000.4 - 2002.3

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  • Keio University   Department of Economics   Bachelor Course

    1996.4 - 2000.3

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Research History

  • Kansai University   Faculty of Informatics   Professor

    2021.4

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  • Wakayama University   Department of Economics   Associate Professor

    2008.4 - 2021.3

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  • Wakayama University   Department of economics   Assistant Professor

    2007.4 - 2008.3

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  • Kyoto University   Institute of Economic Research   Post Doctoral Fellow

    2006.4 - 2007.3

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  • Kobe University   Graduate School of Economics   Lecturer

    2005.4 - 2006.3

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Professional Memberships

Papers

  • Burden Sharing and Self-Enforcing Climate Agreements Reviewed

    Shuichi Ohori, Katsunori Ohta

    Journal of the Association of Environmental and Resource Economists   11 ( 4 )   827 - 852   2024.7

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:University of Chicago Press  

    DOI: 10.1086/727808

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  • Optimal sharing rules in repeated partnerships Reviewed

    Hajime Kobayashi, Katsunori Ohta, Tadashi Sekiguchi

    JOURNAL OF ECONOMIC THEORY   166   311 - 323   2016.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    This paper extends a model of repeated partnerships by Radner et al. (1986) allowing heterogeneous partners to choose their sharing rule. A sharing rule is optimal if the repeated game under the sharing rule has a public strategy equilibrium whose payoff sum is not improved by any public strategy equilibrium under any sharing rule. Two key factors for the analysis are the efficiency loss from allowing only the more productive partner to work and the efficiency loss in any cooperative equilibrium from imperfect observability. If the latter loss is smaller than the former, a threshold discount factor exists below which an asymmetric sharing rule inducing only one partner to work every period is optimal. At the threshold, an optimal sharing rule uniquely exists that is also optimal for any greater discount factor. The latter sharing rule reduces to the equal sharing rule for identical partners. The optimal equilibrium payoff sum as a function of the discount factor is a step function whose jump occurs at the threshold discount factor. (C) 2016 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.jet.2016.09.004

    Web of Science

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  • Optimal collusion under imperfect monitoring in multimarket contact Reviewed

    Hajime Kobayashi, Katsunori Ohta

    GAMES AND ECONOMIC BEHAVIOR   76 ( 2 )   636 - 647   2012.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    We investigate optimal collusion in repeated multimarket contact under imperfect public monitoring, where two firms operate in m markets and in each market, each firm's decision and public signals are binary. We show that in an optimal pure strategy strongly symmetric perfect public equilibrium, the size of efficiency loss is equal to that in the market with the most tempting deviation under single-market contact. Furthermore, we show a sufficient condition under which the symmetric equilibrium is optimal for joint payoff maximization among any perfect public equilibrium. (C) 2012 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.geb.2012.08.003

    Web of Science

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  • Multimarket contact in continuous-time games Reviewed

    Hajime Kobayashi, Katsunori Ohta

    ECONOMICS LETTERS   101 ( 1 )   4 - 5   2008.10

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    This paper investigates whether multimarket contact is effective in increasing the value of collusion. We show that for any discount rate, the set of equilibrium payoffs (average per market) expands through multimarket contact in continuous-time games. (C) 2008 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.econlet.2008.03.031

    Web of Science

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Presentations

  • Repeated Partnerships with Decreasing Returns

    Katsunori Ohta

    The 11th World Congress of The Econometric Society  2015.8 

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    Event date: 2015.8

    Language:English   Presentation type:Oral presentation (general)  

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Research Projects

  • Burden-sharing and self-enforcing international agreements on international public goods provisions

    Grant number:20K01548  2020.4 - 2023.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

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    Grant amount:\3380000 ( Direct Cost: \2600000 、 Indirect Cost:\780000 )

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  • Repeated games and international trade cooperation on non-tariff trade barrier

    Grant number:17K03690  2017.4 - 2020.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    Ohta Katsunori

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    Grant amount:\2080000 ( Direct Cost: \1600000 、 Indirect Cost:\480000 )

    This study considers international cooperation between large countries when we take unobservable trade barriers into consideration. For this purpose, this study uses infinitely repeated games with imperfect public monitoring. In the context of two-country two-commodity models, we can use terms-of-trade as a public signal. Terms-of-trade has a fine property for statistical distinguishability of deviations, because the deviation from an agreement improves the terms-of-trade for the deviator, whereas it changes the opponents terms-of-trade for the worse. We construct a simple asymmetric strategy based on terms-of-trade, which we call safeguard strategy. This study examines the condition that safeguards strategy becomes equilibrium.
    This study also considers international cooperation by asymmetric strategies in the context of international environmental agreements.

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  • Repeated game analysis on long-term partnerships

    Grant number:26780122  2014.4 - 2017.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    OHTA KATSUNORI, KOBAYASHI Hajime, SEKIGUCHI Tadashi

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    Grant amount:\1950000 ( Direct Cost: \1500000 、 Indirect Cost:\450000 )

    We investigate cooperation in teams by theoretical analysis of repeated games with imperfect public monitoring. In particular, we extend the model of repeated partnerships by Radner, Myerson and Maskin (1986, Review of economic Studies) allowing heterogeneous partners to choose and commit their sharing rule to achieve the most efficient equilibrium in the sense of maximizing the partners' total payoffs. We characterize the optimal sharing rule which supports the most efficient equilibrium payoff vector. We also consider the situation where it is not efficient for all members to work, and obtain the necessary and sufficient condition to achieve exact efficiency. Even when the condition fails, we obtain the approximate efficiency result.

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  • Accumulating Information in Repeated Financial Transactions: Theory and Experiment

    Grant number:24530207  2012.4 - 2015.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    KOBAYASHI Hajime, OHTA Katsunori, SAITO Tetsuya, SHICHIJO Tatsuhiro

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    Grant amount:\4550000 ( Direct Cost: \3500000 、 Indirect Cost:\1050000 )

    We investigated a moral hazard problem in financial transactions. Specifically, we consider a repeated prisoner's dilemma between two players in which players can not observe the opponent's action but imperfectly observe signals depending on their actions. We compare efficiency losses in the different timings of releasing information combining with the different levels of noise of signals.
    We found that the level of cooperation decreases as the timing of releasing signal becomes late. This experimental result implies that timely disclosure policy enhances efficiency in financial markets.

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  • Formation of collaboration network in long-term relationships

    Grant number:19730145  2007 - 2008

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    KOBAYASHI Hazime, OHTA Katsunori, SUEHIRO Hideo, SEKIGUCHI Tadashi

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    Grant amount:\1810000 ( Direct Cost: \1600000 、 Indirect Cost:\210000 )

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  • Repeated games and collusive behavior

    Grant number:19730174  2007 - 2008

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    OHTA Katsunori, KOBAYASHI Hajime, SEKIGUCHI Tadashi

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    Grant amount:\690000 ( Direct Cost: \600000 、 Indirect Cost:\90000 )

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