OHTA,Katsunori - Faculty of Informatics Department of Informatics

OHTA, Katsunori

Faculty, Department/Institute

Faculty of Informatics Department of Informatics

Academic status (qualification)

Professor Apr. 1,2021

Undergraduate Degrees・University

Keio University Faculty of Economics2000

Graduate Degrees・University

Kobe University Master's Degree Program 2002
Kobe University Doctor's Degree Program 2005

Academic Degrees

Mar. 2005

Homepage Address, E-mail Address

Homepage Address：https://sites.google.com/site/katsunoriohta15/

Research fields	keyword
Game theory	Repeated Games

所属学会・団体名	役職名 (役職在任期間)
Econometric Society

Research Publications

No.	Type of publication	Date of publication (Date of presentation)	Title	Type of research result	Jointly authored or single authored	Publisher and journal name
1	Papers1	2023～2023,00,00,,,	Burden-sharing and Self-enforcing Climate Agreements	Academic Journal	Co-authored	Journal of the Association of Environmental and Resource Economists
2	Papers1	2016/11～2016,11,00,,,	Optimal Sharing Rules in Repeated Partnerships	Academic Journal	Co-authored	Journal of Economic Theory
3	Papers1	2012/11～2012,11,00,,,	Optimal Collusion under Imperfect Monitoring in Multimarket Contact	Academic Journal	Co-authored	Games and Economic Behavior
4	Papers1	2008/10～2008,10,00,,,	Multimarket Contact in Continuous-time Games	Academic Journal	Co-authored
5	Papers1	2008/1～2008,01,00,,,	Repeated Games with Imperfect Public Monitoring: A Survey	In-house publication	Single-Author
6	Theses26	2005/3～2005,03,00,,,	Applications of Repeated Games with Imperfect Public Monitoring	Other	Single-Author

PapersBurden-sharing and Self-enforcing Climate AgreementsIn refereedAcademic JournalCo-authoredOHTA,Katsunori;OHORI, ShuichiJournal of the Association of Environmental and Resource Economists2023～This study analyzes self-enforcing climate agreements in a repeated-game framework in which asymmetric countries emit greenhouse gases over time. In particular, we consider a novel burden-sharing scheme that makes an agreement self-enforcing even when a relatively less patient country participates in the agreement. The long-term stable emission quota that makes the agreement self-enforcing for the largest set of discount factors equalizes the compliance thresholds across countries. We then show that the long-term stable quota satisfies grandfathering as an equity criterion when countries are asymmetric. This implies that low-emitting countries that have devel- oped clean technologies will be reluctant to agree to the scheme, while countries that have invested in adaptation and brown technology are likely to accept the emission quota. Furthermore, an ambitious target level deteriorates the compliance incentives of countries that are allowed to have low emission reduction rates.

PapersOptimal Sharing Rules in Repeated PartnershipsIn refereedAcademic JournalCo-authoredOHTA,Katsunori;KOBAYASHI, HajimeJournal of Economic Theory2016/11～https://doi.org/10.1016/j.jet.2016.09.004This 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.

PapersOptimal Collusion under Imperfect Monitoring in Multimarket ContactIn refereedAcademic JournalCo-authoredOHTA,Katsunori;KOBAYASHI, HajimeGames and Economic Behavior2012/11～https://doi.org/10.1016/j.geb.2012.08.003We investigate optimal collusion in repeated multimarket contact under imperfect public monitoring, where two firms operate in m markets and in each market, each firmʼs 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.

PapersMultimarket Contact in Continuous-time GamesIn refereedAcademic JournalCo-authoredOHTA,Katsunori;KOBAYASHI, Hajime2008/10～https://doi.org/10.1016/j.econlet.2008.03.031This 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.

PapersRepeated Games with Imperfect Public Monitoring: A SurveyUnrefereedIn-house publicationSingle-AuthorOHTA,Katsunori2008/1～10.19002/AN00071425.341.4304516222

ThesesApplications of Repeated Games with Imperfect Public MonitoringOtherSingle-AuthorOHTA,Katsunori2005/3～

OHTA, Katsunori

Faculty, Department/Institute

Academic status (qualification)

Undergraduate Degrees・University

Graduate Degrees・University

Academic Degrees

Homepage Address, E-mail Address

Research fields

Research Career

Academic Associations

Research Publications

Courses Taught