KEIO RESEARCHERS INFORMATION SYSTEM

Career 【 Display / hide 】

Career 【 Display / hide 】

• 1989.04

  -

  1995.03

  大学助手(経済学部)

• 1995.04

  -

  2007.03

  大学助教授(経済学部)

• 1995.10

  -

  1997.09

  大学経済学部学習指導副主任

• 2001.10

  -

  2002.07

  大学国際センター学習指導主任

• 2007.04

  -

  Present

  Professor (Dept. of Economics)

Academic Background 【 Display / hide 】

Academic Background 【 Display / hide 】

• 1986.03

  Keio University, Faculty of Economics

  University, Graduated

• 1988.03

  Keio University, Graduate School, Division of Economics

  Graduate School, Completed, Master's course

• 1995.09

  Stanford University, Graduate School of Business, Economic Analysis and Policy

  United States, Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide 】

Academic Degrees 【 Display / hide 】

• Docter of Philosophy in Business, Stanford University, Dissertation, 1995.09

Research Areas 【 Display / hide 】

Research Areas 【 Display / hide 】

• Humanities & Social Sciences / Economic theory (Theoretical Economics)

• Humanities & Social Sciences / Economic theory (Game Theory, Microeconomics)

Research Keywords 【 Display / hide 】

Research Keywords 【 Display / hide 】

• Game Theory

• Microeconomics

Research Themes 【 Display / hide 】

Research Themes 【 Display / hide 】

• Farsighted Group Formation, 

  2022.04

  -

  Present

• Accountable Voting Systems and Economics of Rankings, 

  2018.04

  -

  Present

• Theoretical and Experimental Research on Large Society Games, 

  2010.04

  -

  Present

• Voluntary participaton of games and their application to firm reputations, 

  1999

  -

  2006

• learning in games with bounded rationality, 

  1996

  -

  2005

Books 【 Display / hide 】

Books 【 Display / hide 】

• Non-Cooperative Game Theory

  Takako Fujiwara-Greve, Springer, 2015.07

• 非協力ゲーム理論

  GREVE TAKAKO, 東京・知泉書館, 2011.05

• Public Economics: Theory and Practice

  GREVE TAKAKO, 東洋経済新報社, 2003.04

  Scope: 113-142

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• Farsighted Clustering with Group-Size Effects and Reputations

  Takako Fujiwara-Greve, Toru Hokari

  Dynamic Games and Applications （Springer)  13   610 - 635 2022.09

  Research paper (scientific journal), Joint Work, Corresponding author, Accepted

  • Access to Document (DOI)

• Algorithms may not learn to play a unique Nash equilibrium

  Fujiwara-Greve T., Nielsen C.K.

  Journal of Computational Social Science （Journal of Computational Social Science)  4 （ 2 ） 839 - 850 2021.11

  ISSN  24322717

  　View Summary

  There is a widespread hope that, in the near future, algorithms become so sophisticated that “solutions” to most problems are found by machines. In this note, we throw some doubts on this expectation by showing the following impossibility result: given a set of finite-memory, finite-iteration algorithms, a continuum of games exist, whose unique and strict Nash equilibrium cannot be reached from a large set of initial states. A Nash equilibrium is a social solution to conflicts of interest, and hence finite algorithms should not be always relied upon for social problems. Our result also shows how to construct games to deceive a given set of algorithms to be trapped in a cycle without a Nash equilibrium.

  • Access to Document (DOI)

• "Asymmetry of Customer Loss and Recovery under Endogenous Partnerships: Theory and Evidence"

  Takako Fujiwara-Greve, Henrich R. Greve, and Stafan Jonsson

  International Economic Review 57 （ 1 ） 3 - 30 2016.02

  Research paper (scientific journal), Joint Work, Accepted

  　View Summary

  This article is inspired by real-world phenomena that firms lose customers based on imprecise information and take a long time to recover. If consumers are playing an ordinary repeated game with fixed partners, there is no clear reason why recovery happens slowly. However, if consumers are playing an endogenously repeated game, a class of simple efficient equilibria exhibits the asymmetry of fast loss and slow recovery of customers after a bad signal. Exit is systematic, but formation of a new partnership is random. We also give empirical evidence of our equilibria at an individual-firm level.

  • Access to Document (DOI)

• "Efficiency may improve when defectors exist"

  Takako Fujiwara-Greve, Masahiro Okuno-Fujiwara, and Nobue Suzuki

  Economic Theory 60 （ 3 ） 423 - 460 2015.08

  Accepted

  　View Summary

  <p>In repeated Prisoner’s Dilemma, the C-trigger strategy played by all players is well known to achieve symmetric efficiency when players are sufficiently patient. By contrast, if players are free to quit a repeated Prisoner’s Dilemma without information flow to new partners, cooperation from the outset of new partnerships cannot be a part of any symmetric equilibrium. Fujiwara-Greve and Okuno-Fujiwara (Rev Econ Stud 76:993–1021, 2009) showed that symmetric trust-building strategies can constitute an equilibrium for sufficiently long initial (D, D) (trust-building) periods. However, trust-building periods create social loss of payoffs, and there is a possibility that an asymmetric equilibrium with some players cooperating immediately, while others defect, may be more efficient. We show that there is a “fundamentally asymmetric” locally stable Nash equilibrium consisting of the most cooperative strategy (C-trigger with ending the partnership when betrayed) and the most noncooperative strategy, which plays D and ends the partnership immediately. When the deviation gain is relatively small, the fundamentally asymmetric equilibrium is neutrally stable against equilibrium entrants within trust-building strategies and is more efficient than any Nash equilibrium consisting of non-degenerate trust-building strategies. Our result indicates that behavioral diversity can be stable and beneficial for the society, even if players are free to escape from personalized punishments.</p>

  • Access to Document (DOI)

• "Voluntarily separable repeated Prisoner's Dilemma with reference letters"

  Fujiwara-Greve Takako, Okuno-Fujiwara Masahiro, Suzuki Nobue

  Games and Economic Behavior 74 （ 2 ） 504 - 516 2012.03

  Research paper (scientific journal), Joint Work, Accepted,  ISSN  0899-8256

  　View Summary

  <p>We consider the voluntarily separable repeated Prisoner's Dilemma model in which players randomly meet and form pairs to repeatedly play Prisoner's Dilemma only by mutual agreement. While the literature has dealt with the case of no information flow across partnerships, we consider the case in which players can issue a "reference letter" to verify at least that the partnership entered the cooperation phase. We show that such reference letters can be voluntarily provided by the partners even at some cost, and that the sheer existence of a letter shortens the trust-building periods and thus improves social efficiency. © 2011 Elsevier Inc.</p>

  • Access to Document (DOI)

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Papers, etc., Registered in KOARA 【 Display / hide 】

Papers, etc., Registered in KOARA 【 Display / hide 】

• 2023 Econometric Society Asian School in Economic Theory (1)

  Fujiwara-Greve, Takako

  Mita journal of economics （慶應義塾経済学会)  116 （ 3 ） 311 (107) - 323 (119) 2023.10

  ISSN  00266760

• Announcement of halting of the publication of Keio economic studies

  Fujiwara-Greve, Takako

  Keio economic studies （Keio Economic Society, Keio University)  56   1 - 2 2023

  ISSN  00229709

• On stochastic acceptance and gradual cooperation in voluntarily repeated prisoner's dilemma with no information flow

  Fujiwara-Greve, Takako

  Keio journal of economics （慶應義塾経済学会)  101 （ 3 ） 465(69) - 489(93) 2008.10

  ISSN  00266760

• Game Theoretic Analysis of Trust and Social Norms in Voluntarily Formed Networks

  GREVE, TAKAKO

  科学研究費補助金研究成果報告書 2008

• Efficiency of voluntary partnerships with no information flow

  Fujiwara-Greve, Takako

  Keio journal of economics （慶應義塾経済学会)  93 （ 3 ） 515(3) - 521(9) 2000.10

  ISSN  00266760

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Presentations 【 Display / hide 】

Presentations 【 Display / hide 】

• Tolerance and Behavioral Diversity

  FUJIWARA-GREVE TAKAKO

  SAET Meeting (Academia Sinica, Taiwan) , 

  2018.06

  , 

  Oral presentation (general), Society for the Advancement of Economic Theory

• Tolerance and Behavioral Diversity

  FUJIWARA-GREVE TAKAKO

  Dynamic Models in Economics: Workshop on Game Theory (Institute for Mathematical Sciences, National University of Singapore) , 

  2018.06

  , 

  Oral presentation (invited, special), Institute for Mathematical Sciences, National University of Singapore

• Tolerance and Behavioral Diversity

  FUJIWARA-GREVE TAKAKO

  The 2018 Arne Ryde conference and mini course on Learning, Evolution and Games (Lund University, Sweden) , 

  2018.06

  , 

  Oral presentation (invited, special), Arne Ryde Foundation

• Exit Option Can Make Cooperation Easier

  FUJIWARA-GREVE TAKAKO

  The Second Asia-Pacific Industrial Organisation Conference (APIOC 2017) (University of Auckland, New Zealand) , 

  2017.12

  , 

  Oral presentation (invited, special), ASIA-PACIFIC Industrial Organisation Society

• Long-term Cooperation and Diverse Behavior Patterns under Voluntary Partnerships

  FUJIWARA-GREVE TAKAKO

  European Meeting of the Econometric Society (ISCTE - IUL and the University of Lisbon) , 

  2017.08

  , 

  Oral presentation (general), Econometric Society

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

Research Projects of Competitive Funds, etc. 【 Display / hide 】

• Theory and Experiment of Social Games: Voluntary Cooperation, Diverse Strategies, and International Comparison

  2017.04

  -

  2021.03

  JSPS, Grant-in-Aid for Scientific Research, Takako Fujiwara-Greve, Research grant, Principal investigator

Awards 【 Display / hide 】

Awards 【 Display / hide 】

• Graeme Woodbridge Prize

  Takako Fujiwara-Greve, Yosuke Yasuda, 2022.12, Asia-Pacific Industrial Organization Society, Inspecting Cartels over Time: With and without Leniency Program

  Type of Award： Award from international society, conference, symposium, etc.

Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• TOPICS IN MICROECONOMICS

  2024

• SEMINAR: MICROECONOMICS

  2024

• SEMINAR: MATHEMATICS FOR ECONOMICS

  2024

• RESEARCH SEMINAR D

  2024

• RESEARCH SEMINAR C

  2024

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Social Activities 【 Display / hide 】

Social Activities 【 Display / hide 】

• Associate member, Science Council of Japan

  2014.10

  -

  Present

Memberships in Academic Societies 【 Display / hide 】

Memberships in Academic Societies 【 Display / hide 】

• Game Theory Society, 

  2000.04

  -

  Present

• American Economic Association, 

  1997.09

  -

  Present

• Econometric Society, 

  1995.09

  -

  Present

• Japanese Economic Association, 

  1993.07

  -

  Present

Committee Experiences 【 Display / hide 】

Committee Experiences 【 Display / hide 】

• 2020.06

  -

  Present

  監事, 日本経済学会

• 2014.06

  -

  2016.06

  総務理事, 日本経済学会