Updated on 2024/12/21

写真a

 
ISHIKAWA, Ryuichiro
 
Affiliation
Faculty of International Research and Education, School of International Liberal Studies
Job title
Professor
Degree
Ph. D. in Economics ( Hitotsubashi University )

Research Experience

  • 2020.04
    -
    Now

    Waseda University   Faculty of International Research and Education   Professor

  • 2016.04
    -
    2020.03

    Waseda University   School of International Liberal Studies   Associate Professor

  • 2013.04
    -
    2016.03

    University of Tsukuba   Faculty of Engineering, Information, and Systems   Associate Professor

  • 2014.04
    -
    2015.03

    University of California, Davis   Department of Economics   Visiting Scholar

  • 2011.10
    -
    2013.03

    University of Tsukuba   Faculty of Engineering, Information, and Systems   Assistant Professor

  • 2005.04
    -
    2011.09

    University of Tsukuba   Graduate School of Systems and Information Engineering   Assistant Professor

  • 2003.04
    -
    2005.03

    Japan Society for the Promotional Science   Postdoctoral Fellow

  • 2003.08
    -
    2005.01

    University of California, Berkeley   Department of Economics   Postdoctoral Fellow

  • 2002.04
    -
    2003.03

    Hitotsubashi University   Faculty of Economics   Research Associate

▼display all

Education Background

  • 1999.04
    -
    2002.03

    Hitotsubashi University   Graduate School of Economics  

  • 1997.04
    -
    1999.03

    Hitotsubashi University   Graduate School of Economics  

  • 1993.04
    -
    1997.03

    Science University of Tokyo   Faculty of Management  

Professional Memberships

  •  
     
     

    THE JAPANESE SOCIETY FOR ARTIFICIAL INTELLIGENCE

  •  
     
     

    Research Center for Mathematical Economics

  •  
     
     

    Econometric Society

  •  
     
     

    JAPANESE ECONOMIC ASSOCIATION

Research Areas

  • Economic theory

Research Interests

  • Game Theory

  • Experimental Economics

  • Economics of Information

Awards

  • Best Paper Award

    2011.08   12th International Conference on Global Business and Economic Development (SGBED)  

  • 教育貢献賞

    2009   筑波大学システム情報工学研究科  

 

Papers

  • A quantitative easing experiment

    Adrian Penalver, Nobuyuki Hanaki, Eizo Akiyama, Yukihiko Funaki, Ryuichiro Ishikawa

    Journal of Economic Dynamics and Control   119   103978 - 103978  2020.10  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • Service Switching in Case-based Decisions following Bad Experiences: Online reviews data of Japanese hairdressing salons

    Hiroki Takahashi, Nariaki Nishino, Ryuichiro Ishikawa

    CEUR-WS Proceedings on ICCBR 2019 Workshop on Process-Oriented Case-Based Reasoning   2567   74 - 84  2020.03  [Refereed]

  • Dynamic Game Logic of Communication*

    Ryuichiro Ishikawa

    Transactions of the Institute of Systems, Control and Information Engineers   32 ( 12 ) 429 - 438  2019.12  [Refereed]

     View Summary

    This paper provides a game theoretical framework to analyze speech acts in rules-based communication places such as Parliamentary debates and Bibliobattle. The game consists of two stages: (1) the first stage of deliberation, and (2) the second stage of resolution. In the first stage, players discuss a common topic from various viewpoints, and in the second stage all the participants decide which opinion is plausible following a social choice rule as voting. The theory to examine the game involves dynamic epistemic logic (so-called dynamic game logic), and then enables us to focus on players’ epistemic states through speech acts. Furthermore, it is connected to a part of mechanism design in the second stage, and secures players’ incentives compatibility in social decisions. As a result, it captures how the rules work and what kind of speeches in speech places are derived through players’ strategic thinking with rationality.

  • Inductive Game Theory and Logical Positivism

    Ryuichiro Ishikawa

    Waseda Global Forum   14   41 - 60  2018.03

     View Summary

    Inductive game theory is a branch of game theory. This theory captures how individual experiences are reflected into their decisions. From the viewpoint, the theory answers why individuals have different/various views for an identical situation, and establishes the foundation of incomplete information games with a prior. In this sense, it is related to logical positivism in the 20th century. This is because the logical positivism was a branch of empiricism and the methodology is affected by modern logic since F. L. G. Frege, B. A. W. Russell and A. N. Whitehead. Since a branch of game theory also employs mathematical logic (called Game Logic), the philosophy of the logical positivism will offer new insights to the methodology and the research targets on game theory.
    In this paper, I raise the methodology that inductive game theory should seek from the viewpoint of logical positivism. Furthermore, I show that the inductive game theory needs the relationship to social institutions. My first suggestion is how the theory can capture others minds in a player’s own mind. This is because inductive game theory does not involve universal belief/type space of the standard incomplete information games. I put forward a proposal to introduce others’ mind.
    As generally known, the logical positivism was finally criticized by W. V. O. Quine and others, and is regarded as failure. Then, I will reach the second suggestion; how the failure is related to inductive game theory. In the suggestion, I state that the failure is not the problem in inductive game theory, but it emphasizes the importance to develop “Economics of institutions and recognition”. We conclude that the failure is overcome by considering interactions between individuals and societies in inductive game theory.

  • Effects of different ways of incentivizing price forecasts on market dynamics and individual decisions in asset market experiments

    Nobuyuki Hanaki, Eizo Akiyama, Ryuichiro Ishikawa

    Journal of Economic Dynamics and Control   88   51 - 69  2018.03  [Refereed]

     View Summary

    In this study, we investigate (a) whether eliciting future price forecasts influences market outcomes and (b) whether differences in the way in which subjects are incentivized to submit “accurate” price forecasts influence market outcomes as well as the forecasts in an experimental asset market. We consider four treatments: one without forecast elicitation and three with forecast elicitation. In two of the treatments with forecast elicitation, subjects are paid based on their performance in both forecasting and trading, while in the other treatment with forecast elicitations, they are paid based on only one of those factors, which is chosen randomly at the end of the experiment. We found no significant effect of forecast elicitation on market outcomes in the latter case. Thus, to avoid influencing the behavior of subjects and market outcomes by eliciting price forecasts, paying subjects based on either forecasting or trading performance chosen randomly at the end of the experiment is better than paying them based on both. In addition, we consider forecast-only experiments: one in which subjects are rewarded based on the number of accurate forecasts and the other in which they are rewarded based on a quadratic scoring rule. We found no significant difference in terms of forecasting performance between the two.

    DOI

    Scopus

    23
    Citation
    (Scopus)
  • Behavioral uncertainty and the dynamics of traders’ confidence in their price forecasts

    Nobuyuki Hanaki, Eizo Akiyama, Ryuichiro Ishikawa

    Journal of Economic Dynamics and Control   88   121 - 136  2018.03  [Refereed]

     View Summary

    By how much does the presence of behavioral uncertainty in an experimental asset market reduce subjects’ confidence in their price forecasts? An incentivized interval forecast elicitation method is employed to answer this question. Each market consists of six traders, and the value of dividends is known. Two treatments are considered: six human traders (6H), and one human interacting with five computer traders whose behavior is known (1H5C). We find that while the deviation of the initial price forecasts from fundamental value is smaller in the 1H5C treatment than in the 6H treatment, albeit not statistically significantly, the average confidence regarding the forecasts is not. We further analyze the relationships between subjects’ confidence in their forecasts and their trading behavior, as well as their trading performance, in the 6H treatment. While subjects’ high confidence in their short-term forecasts shows a negative correlation with their trading performance, high confidence in their long-term forecasts shows a positive correlation with trading performance.

    DOI

    Scopus

    7
    Citation
    (Scopus)
  • It is Not Just Confusion! Strategic Uncertainty in An Experimental Asset Market

    Eizo Akiyama, Nobuyuki Hanaki, Ryuichiro Ishikawa

    The Economic Journal   127 ( 605 ) F563 - F580  2017.10  [Refereed]

    DOI

    Scopus

    46
    Citation
    (Scopus)
  • Heterogeneous Information in Experimental Asset Markets

    H. Tsuruzono, Y. Fujii, T. Goto, Y. Hattori, R. Ishikawa

    Osaka Sangyo University Journal of Economics   16 ( 1-2 ) 23 - 35  2015  [Refereed]

     View Summary

    In the standard economic theory, informed traders have more advantages in economic activities than uninformed ones. In particular, it seems obvious that one can obtain more gains in financial markets by having more information about the fundamental values of an asset. This study examines whether better-informed traders have an advantage over less-informed ones by conducting experimental asset markets following Huber, et al. (2008, Journal of Economic Behavior & Organization). Our experiments show that better-informed traders do not necessarily gain more than less-informed ones.

    CiNii

  • How do experienced traders respond to inflows of inexperienced traders? An experimental analysis

    Eizo Akiyama, Nobuyuki Hanaki, Ryuichiro Ishikawa

    JOURNAL OF ECONOMIC DYNAMICS & CONTROL   45   1 - 18  2014.08  [Refereed]

     View Summary

    We conducted asset market experiments where one experienced subject interacts with five inexperienced subjects to investigate how experienced subjects change their price forecasts and trading behavior when faced with strategic uncertainty caused by inflows of inexperienced subjects. Only half the experienced subjects initially forecasted prices deviating more from the fundamental values in the market with five inexperienced subjects than in the final round of the experiment in which they had previously participated. Furthermore, the majority of our experienced subjects did not change their trading behavior. Many experienced subjects act as price stabilizers when the inflow of inexperienced subjects is not associated with other changes in market conditions. (C) 2014 Elsevier B.V. All rights reserved.

    DOI

    Scopus

    23
    Citation
    (Scopus)
  • How Does Childbirth Alter Intrahousehold Resource Allocation? Evidence from Japan

    Tomoki Fujii, Ryuichiro Ishikawa

    OXFORD BULLETIN OF ECONOMICS AND STATISTICS   75 ( 3 ) 362 - 387  2013.06  [Refereed]

     View Summary

    Exploiting unique panel data that include direct measurements of resource allocation within households, we investigated the impact of childbirth on intrahousehold allocation for married Japanese couples. Based on a collective model of the household, we developed reduced-form and structural-form estimation equations that allow us to focus on private goods to track the changes in intrahousehold resource allocation. We found one additional child is associated with a reduction in the wife's private expenditure share by at least two percentage points. This may be because she substitutes more say in decisions on the children for her own private expenditure share.

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • A note on separability and intra-household resource allocation in a collective household model

    Tomoki Fujii, Ryuichiro Ishikawa

    REVIEW OF ECONOMICS OF THE HOUSEHOLD   11 ( 1 ) 143 - 149  2013.03  [Refereed]

     View Summary

    This paper shows that it is possible to track the changes in the distribution of power within a couple by focusing on the changes in the pattern of private consumption when the consumption decisions are efficient and private consumption is separable from public consumption in individual preferences. We first show that the separability of private consumption from public consumption at the individual level carries over to the household level. Hence, changes in public consumption only matters through a change in the residual budget available for private consumption. When the consumption decisions within the household is efficient, private consumption decisions can be modeled as the solution of a problem consisting in maximizing a weighted sum of the private-consumption sub-utility functions of the spouses under the residual budget, the weights being unique and representing the distribution of power over the allocation of private consumption. The model presented in this paper can be used to analyze the changes in the household resource allocation due to, for example, childbirth.

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • Arrow-Fisher-Hanemann-Henry and Dixit-Pindyck option values under strategic interactions

    T. Fujii, R. Ishikawa

    Strategic Behavior and the Environment   3 ( 3 ) 169 - 183  2013  [Refereed]

    DOI

  • Interbank market contagion by mark-to-market accounting

    T. Ishikawa, R. Ishikawa

    n 24th Asian-Pacific Conference on International Accounting Issues    2013  [Refereed]

  • Inductive game theory: A simulation study of learning a social situation

    E. Akiyama, R. Ishikawa, M. Kaneko, J. J. Kline

    Game Theory Relaunched   Chapter 3   55 - 76  2013  [Refereed]

    DOI

  • Revision of beliefs with perceived experiences

    Y. Fujii, R. Ishikawa

    Annual Research Bulletin of Osaka Sangyo University   5 ( March ) 45 - 70  2013  [Refereed]

     View Summary

    We consider a revision process of personal beliefs with perceived experiences. A player revises his old beliefs on his environment into new ones with the currently stored perceived experiences. A salient point of our theory is to take the personal experiences into belief revision. Both the beliefs and perceived experiences are formulated in the same mathematical manner. In this setting, we consider three kinds of belief changes, e-expansion, e-contraction and e-revision. We prove the Levi identity by these changes considering the perceived experiences, i.e., the e-revision is expressed in terms of the e-expansion and e-contraction. Thus, the revision of a player's personal view is characterized under his experiences.

    CiNii

  • A Simulation Study of Learning a Structure Mike's Bike Commuting

    M. Kaneko, J. J. Kline, E. Akiyama, R. Ishikawa

    Proceedings of 2nd International Conference on Simulation and Modeling Methodologies, Technologies     208 - 217  2012  [Refereed]

  • Quasi-option value under strategic interactions

    Tomoki Fujii, Ryuichiro Ishikawa

    RESOURCE AND ENERGY ECONOMICS   34 ( 1 ) 36 - 54  2012.01  [Refereed]

     View Summary

    We consider a simple two-period model of irreversible investment under strategic interactions between two players. In this setup, we show that the quasi-option value may cause some conceptual difficulties. In case of asymmetric information, decentralized investment decisions fail to induce first-best allocations. Therefore a regulator may not be able to exercise the option to delay the decision to develop. We also show that information-induced inefficiency may arise in a game situation and that under certain assumptions inefficiency can be eliminated by sending asymmetric information to the players, even when the regulator faces informational constraints. Our model is potentially applicable to various global environmental problems. (C) 2011 Elsevier B.V. All rights reserved.

    DOI

    Scopus

  • Difference between AFHH and DP option values under strategic interactions

    T. Fujii, R. Ishikawa

    12th International Conference on Global Business and Economic Development    2011  [Refereed]

  • Belief revision for inductive game theory

    K. Hasebe, R. Ishikawa

    9th European workshop on Multi-Agent Systems    2011  [Refereed]

  • Learning games

    Nobuyuki Hanaki, Ryuichiro Ishikawa, Eizo Akiyama

    JOURNAL OF ECONOMIC DYNAMICS & CONTROL   33 ( 10 ) 1739 - 1756  2009.10  [Refereed]

     View Summary

    This paper presents a model of learning about a game. Players initially have little knowledge about the game. Through playing the same game repeatedly, each player not only learns which action to choose but also constructs a personal view of the game. The model is studied using a hybrid payoff matrix of the prisoner's dilemma and coordination games. Results of computer simulations show that (1) when all the players are slow at learning the game, they have only a partial understanding of the game, but might enjoy higher payoffs than in cases with full or no understanding of the game; (2) when one player is quick in learning the game, that player obtains a higher payoff than the others. However, all can receive lower payoffs than in the case in which all players are slow learners. (C) 2009 Elsevier B.V. All rights reserved.

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • コンピューター実験:新しい理論分析への招待 (by 花木伸行, 秋山英三, 石川竜一郎)

    花木伸行, 秋山英三, 石川竜一郎

    経済セミナー   ( 642 ) 29-32  2008.10

  • Rational expectations can preclude trades

    T. Matsuhisa, R. Ishikawa

    Advances in Mathematical Economics   11   105 - 116  2008  [Refereed]

    DOI

  • No trades under rationality about expectations

    Takashi Matsuhisa, Ryuichiro Ishikawa

    PROCEEDINGS OF THE 25TH INTERNATIONAL CONFERENCE ON MATHEMATICAL METHODS IN ECONOMICS 2007     204 - 211  2007  [Refereed]

     View Summary

    We reconsider the no trade theorem in an exchange economy where the traders have non-partition information from aspect of rough sets. By introducing a new concept, rationality of expectations, we show some versions of the theorem different from previous works, such as Geanakoplos (1989, Came theory without partitions, and applications to speculation and consensus, Cowles Foundation Discussion Paper No. 914).

  • Communication protocols with belief messages

    R Ishikawa

    THEORY AND DECISION   61 ( 1 ) 63 - 74  2006.08  [Refereed]

     View Summary

    This paper presents a communication protocol to reach consensus. In our setting, every player has asymmetric information and evaluates a fixed event on his information. According to the protocol, the sender sends non-partitional messages that he believes the event with a probability of at least his evaluation. We show that the posteriors for the event must be equal among the players after the communication.

    DOI

    Scopus

  • Core Equivalence in Economy under Generalized Information

    T. Matsuhisa, R. Ishikawa, Y. Hoshino

    Proceedings of the Third International Conference on Nonlinear Analysis and Convex Analysis     277 - 288  2004  [Refereed]

  • Rationality of final decisions leads to sequential equilibrium

    R Ishikawa, T Matsuhisa

    ICM MILLENNIUM LECTURES ON GAMES     193 - 204  2003  [Refereed]

     View Summary

    This article investigates epistemic conditions for a sequential equilibrium in an extensive form game with imperfect information: If players mutually know that all players maximize own expected payoffs for any information sets in their final decisions, then their behaviors with belief yield a sequential equilibrium. This result is an extension of [2] in a perfect information game. In this article, we propose the notion of mu-rationality, by which we mean that player knows that he maximizes his own payoff according to the common-belief mu. We also introduce the notion of mu-consistency in imperfect information game. Our main theorem states that mutual knowledge of both mu-rationality and mu-consistency induces a sequential equilibrium outcome in an extensive form game.

    DOI

  • Rationality on the Final Decisions Leads to Sequential Equilibrium

    R. Ishikawa, Takashi Matsuhisa

    L.A. Petrosjan et al (Editors): Proceedings of The Tenth International Conference of Dynamic Games (ISDG2002), St. Petersburg (Russia). 2002     379 - 384  2002

  • Rational Expectation Can Preclude Trades

    Takashi Matsuhisa, R. Ishikawa

    L.A. Petrosjan et al (Editors): Proceedings of The Tenth International Conference of Dynamic Games (ISDG2002), St. Petersburg (Russia) 2002     552 - 561  2002

  • Rationality on final decisions leads to sequential equilibrium

    R. Ishikawa, T. Matsuhisa

    Internatinal Congress of Mathematicians, Game theory and Applications Satellite conference   Proceedings volume   251 - 262  2002  [Refereed]

  • Consensus on p-belief communication

    R. Ishikawa, T. Matsuhisa, Y. Akagawa

    International Journal of Applied Mathematics   8 ( 2 ) 159 - 170  2002  [Refereed]

▼display all

Books and Other Publications

  • コミュニケーション場のメカニズムデザイン

    谷口 忠大, 石川 竜一郎, 中川 智皓, 蓮行, 井之上 直也, 末長 英里子, 益井 博史( Part: Joint editor)

    慶應義塾大学出版会  2021.10 ISBN: 4766427734

    ASIN

  • 制度と認識の経済学

    船木 由喜彦, 石川 竜一郎( Part: Joint editor)

    NTT出版  2013.08 ISBN: 4757123124

    ASIN

  • 社会工学が面白い―学際学問への招待

    筑波大学理工学群社会工学類( Part: Contributor)

    開成出版  2009.08 ISBN: 4876033919

    ASIN

Research Projects

  • Bounded intelligence in narrow and wider senses in game theoretical studies

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2021.04
    -
    2026.03
     

  • メカニズムデザインの実践に向けたフィールド実験基盤の構築と活用

    日本学術振興会  科学研究費助成事業

    Project Year :

    2022.04
    -
    2025.03
     

    西野 成昭, 木見田 康治, 竹中 毅, 石川 竜一郎, 栗野 盛光

  • Information acquisition and recommendation systems for consumption of experiential goods

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2020.04
    -
    2024.03
     

  • Optimal rules in pragmatics of argumentation: A view from game theory and logic

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2020.09
    -
    2023.03
     

  • Mechanism design of collective wisdom on inductive learning: Theory, experiments and simulations

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2020.07
    -
    2023.03
     

  • 情報の非対称性と多様な期待形成がもたらす金融市場への影響とその安定化政策について

    日本学術振興会 

    Project Year :

    2018.10
    -
    2023.03
     

  • Development of a Unified Decision-Making Model Based on probabilistic Logic Learning and Its Application to Experimental Economic Data

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2017.06
    -
    2020.03
     

    Ishikawa Ryuichiro

     View Summary

    I constructed a decision theory on inductive approach and examine empirical and experimental data of trades and consumptions. In the construction of a theory, I introduce unawareness structure into dynamic game logic and distinguish two different information: new information and information which an agent already holds but is not aware of the relevance. The theory gives a foundation of a behavioral model to explain their trades.
    In the experimental and empirical analyses, I examined the trade data in experimental asset markets and the consumption data of experience goods. In asset market trading, I observed that the confidence level of the traders' forecasts activates asset trading. Although the empirical goods consumption data did not provide data on confidence in the satisfaction predictions that consumption brings about, we observed consumption behavior with high price sensitivity.

  • 制度・認識・社会正義の経済学の構築に向けて

    日本学術振興会  科学研究費助成事業

    Project Year :

    2014.04
    -
    2019.03
     

     View Summary

    [金子守]制度・認識の問題を限定合理性の立場から考察した。特に、期待効用理論において確率の使用を限定する事を研究した。それによって、アレーのパラドックスのより良い理解とパラドックスからの回避を議論し、制度・認識のより良い理解が得られた。また、船木氏、竹内氏と実験の立場から帰納的ゲーム理論を考察した。[船木由喜彦]実験研究、協力ゲーム研究共に進展し、新しい知見が得られた。国際学会、国内学会でそれらの研究成果を報告した。[鈴木信行]ゲーム理論的な状況における意思決定過程の論理学的分析に関して、構成的推論の観点から研究した。omniscience principlesを中間述語論理の枠組みで研究し、omniscience principlesと中間述語論理の関係について、一定の結果を得た。[秋山英三]主体間の繋がりに濃淡があるネットワーク上において囚人ジレンマがプレイされる系に関して分析を行い、小規模な集団でLink-weightの異質性が協力進化に促すための条件を導出し、大規模集団でもその条件がある程度成立することを計算機シミュレーションで示した。市場取引を抽象化した少数派ゲームの計算機シミュレーションによる分析を行い、参加周期の異なるプレイヤが混在するケースで長期トレーダーが有利になる条件を導出した。[石川竜一郎]資産取引実験を行った。実験において、異なる論理能力を持つ被験者が同一市場で資産取引を行なった時、資産価格にどのように影響するか、資産価格バブルを助長するかという事が焦点になった。同一市場に参加する被験者の論理能力が多様であるほど、資産価格バブルは助長されるということが分かった。[竹内あい]帰納的ゲーム理論と献血に関する実験研究を行った。前者に関して、論文の修正を行っている。分析単位をグループから個人に切り替え、個人レベルでの行動の収束先に関する分析を行った。金子守・鈴木信行・Tai-Wei Hu (海外共同研究者)は認識論理学において加算無限個の命題の連言(&)を許す体系を発展させている。既存の体系とは異なり、有限的体系から構成されており、さらに体系の大きさの順序により階層をなすことが示されている。これにより、「共通認識」の取り扱いが単純になり、帰納的ゲーム理論との結びつきも明らかにすることが期待できる。金子守、竹内あい(分担者)、船木由喜彦(分担者)、Jeffrey Kline (海外共同研究者)は帰納的ゲーム理論における実験に結果の分析に長い時間を要したが、研究の方向性が明確になってきており、今年度中に論文にまとめられる目途がついてきた。石川竜一郎(分担者)は帰納的ゲーム理論において、経験からの知識の改訂・社会的分業の問題を考察してきて、これと分析哲学との関連を考察してきた。これによって、帰納的ゲーム理論の分析哲学・社会経済学における立場が明確になりつつある。これも個人認識のあり方(社会構造の個人の学習)を明確にする。以上は当研究課題の参加者達の研究の一部である。それらを国際研究集会と国内の研究集会において報告・議論し、国際的な研究者達によって吟味してもらった。具体的には、平成28年10月7日~8日に、第9回太平洋ゲーム理論カンファレンスを早稲田大学SGU実証政治学拠点との共催で開催した。ニューヨーク州立大学ゲーム理論センターの Pradeep Dubey教授を招聘し、Peter Wakker教授(Erasmus大学)、Rabah Amier(Iowa大学)教授による報告など最先端の研究成果を発表し、議論を行った。平成29年3月21日に、研究会:社会慣習・行動パターン・限定合理性を開催し、社会経済問題と限定合理性に関して議論を行った。制度・認識・社会正義という研究対象は今まで通りとするが、本プロジェクトの過去3年間の進展に合わせて、より詳細にまたより広い視野から制度・認識・社会正義の研究を進めたい。特に、限定合理性は当プロジェクトにとって重要なキー概念になることが昨年度の研究で分かってきている。ただ、この場合、限定合理性はH. Simon の限定合理性より広い意味で理解する。例えば、論理能力、個別事象の記憶、パターンの記憶等である。これは社会制度や広い意味での社会的分業の問題に関連している。今まで、社会正義の問題は殆ど手を付けてこなかった。平成28年度中に進展させた確率使用を限定した期待効用理論がほぼ完成したので、これを基礎にしたナッシュ社会厚生関数の理論を発展させる予定である。これにより社会正義の問題を語る基礎付けが可能になる。具体的には、ナッシュ社会厚生関数が基礎とする効用の基数性を導くのに必要な確率は、どの程度必要かが分析できる。実は、あまり深い(詳細)確率は必要としないことが導かれると予想している。また、賃貸住宅市場論での市場均衡価格の分布の計算機プログラムで、計算を視覚的にするプログラムの開発を金子守・秋山英三が計画している。これは同時に市場均衡理論に出てくる経済主体を「限定合理性」の立場から論ずることにもなり、市場均衡理論と帰納的ゲーム理論との接続を可能にする。平成29年9月に第10回太平洋ゲーム理論カンファレンスを開催する予定である。3年間の成果を報告して、参加者からコメント・評価をもらい、今後の研究につなげたい。このコンファレンスの参加者は、国内・国外から20名程度である。その他、定期的にゲーム理論・経済学・認識論理学の研究会を計画している

  • Inductive learning theory and its application to experimental asset markets

    Project Year :

    2014.04
    -
    2018.03
     

     View Summary

    The purpose of this project is to construct inductive learning theory to describe learning process of bounded rational decision makers, which is based on their experiences. We focused on experimental asset markets, and analyzed their behavioral data for the following purposes: (i) Classification of subjects’ rationality, (ii) Extraction of effects of their higher order beliefs, (iii) Their predictions of future prices, and (iv) Effects of their heterogeneous experiences. As a result, we found that the bubble of asset prices is facilitated by heterogeneous cognitive abilities, and is due to subjects’ higher order beliefs. Furthermore, we also observed that the experienced subjects in experimental markets adaptively learn price paths in their present markets. In addition, we show a new methodology of experimental assets markets to control subjects’ incentive when they have more incentives

  • Theoretical and Experimental studies on Financial contagion due to Accounting system

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2014.04
    -
    2016.03
     

    Ishikawa Ryuichiro

     View Summary

    In this study, I have both theoretical and experimental studies on mark-to-market accounting systems. In the theoretical work, I show that the system encourages financial contagion, and that banks will go bankrupt even when the banks prepare the liquidity crises.In the experimental work, we have experiments to study how subjects recognize the public information of accounting. The, we have the following results: (1) the subjects who have more information do not necessarily obtain the higher rewards, and (2) When the subjects obtains the higher rewards, they have the better strategy due to the information advantage

  • Voting Outcomes in Public Facility Location Problems

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2013.04
    -
    2015.03
     

    OHSAWA Yoshiaki, ISHIKAWA Ryuichiro, KOBAYASHI Takafumi

     View Summary

    In order to take account of the impact of voters' spatial location, this project is an attempt to characterize the gap between voting location and optimal one by using a simple public facility location model. First, we derive the necessary and sufficient conditions that the voting outcome coincides with efficient one. Then we give simple examples which reveal the inefficiency of the voting solutions. Third we theoretically demonstrate that the network model can reduce to the linear model, indicating that our findings are applicable to network location problems. Finally, we apply our model to an actual city hall location problems in Kanto Region, Japan, using visualization techniques based on GIS

  • 資産価格バブルの発生メカニズムの実験経済学による分析

    日本証券財団 

    Project Year :

    2012.04
    -
    2015.03
     

  • フランス国立研究機構 (ANR):エージェントシミュレーション研究に関する認識論的基礎付け

    日本学術振興会  科学研究費助成事業

    Project Year :

    2011.04
    -
    2015.03
     

  • 時価会計制度がもたらす金融危機波及に関する研究

    公益財団法人稲盛財団  研究助成金

    Project Year :

    2013.04
    -
    2014.03
     

  • 状況認識と行動学習の相互作用に関する2国間比較

    日本学術振興会  科学研究費助成事業

    Project Year :

    2011.04
    -
    2014.03
     

  • Role of higher order beliefs in decision making: Inductive approach

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2011.04
    -
    2014.03
     

    ISHIKAWA Ryuichiro

     View Summary

    The productions of this project are classified into either theoretical ones and experimental economic ones. In theoretical productions, we propose a framework of dynamic logic for inductive game theory. In addition, we study how the difference of information decision makers obtain makes an impact on decision making and how the social welfare varies.In experimental economic productions, we study how subjects expect asset prices through their experiences and cognitive abilities. This is an application of the theoretical products for experimental asset markets. As a result, we found the subjects who get higher score in a cognitive ability test make a greater impact on strategic uncertainty

  • game theory

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2009.04
    -
    2014.03
     

    KANEKO Mamoru, AKIYAMA Eizo, SUZUKI Nobu-yuki, ISHIKAWA Ryuichiro

     View Summary

    In this research project, we have studied social institutions from those in the broad sense such as customs, and moralities to those in the narrow sense such as legal and economic institutions having written codes. Studies of those enable us to make comparisons between societies with different cultural backgrounds. Taking those problems as concrete objects, we conducted research extensively on inductive game theory, epistemic logic, and experimental studies

  • Theoretical Analysis of an Economic System with Information andTransaction Networks in Market Economies

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2010.04
    -
    2013.03
     

    YAMAZAKI Akira, HOSHINO Yoshiaki, ISHIKAWA Ryuichirou

     View Summary

    As a theoretical model of competitive transaction network, a model of ‘Wicksellian Transaction Networks’ is constructed wherein various competitive transaction structures affect resulting outcome of competition within the network. A Wicksellian Transfer Game is introduced on the basis of a model of Wicksellian transaction networks and power distributions among buyers and sellers as their number in the game varies are analyzed

  • 時価会計制度がもたらす金融危機波及に関する研究

    石井記念証券  研究振興財団研究助成金

    Project Year :

     
    -
    2012.04
     

  • 資産価格バブル発生メカニズムの解明

    日本経済研究奨励財団  奨励金

    Project Year :

    2011.04
    -
    2012.03
     

  • Market trade under uncertainty and inductive game theory : Role of Experience and cognition

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2009.04
    -
    2011.03
     

    ISHIKAWA Ryuichiro

     View Summary

    This project analyzes market trade under uncertainty by focusing "private information" and "higher order beliefs." I analyze how acquisition of private information gives impacts to traders' higher order beliefs and asset prices. In addition, I theoretically show how the difference of economic welfare by how a policy maker understands traders' payoffs

  • A study on disability in a socio-economic context: toward a unified social science

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2007
    -
    2011
     

    MATSUI Akihiko, KANEKO Takahiro, KAWAGOE Toshiji, SEKIGUCHI Yohei, TANAKA Emiko, NISHIKURA Miki, FUKUSHIMA Satoshi, MORI Soya, MOROZUMI Ryoko, II Masako, ISHIKAWA Ryuichiro, OKAZAKI Tetuji, SAWADA Yasuyuki, SHIMIZU Takashi, TOYAMA Mayo, NAGAE Akira, HOSHIKA Ryoji, YAMASHITA Mai, USUI Kumiko, KANO Kazuko, KAWASHIMA Satoshi, KAWAMURA Machiko, KURAMOTO Tomoaki, KURIHARA Fusae, SAKAHARA Kiri, SATO Takashi, SEYAMA Noriko, NAGASE Osamu, YAMAMORI Tetsuo

     View Summary

    We focus not only on “people with disability (PwD)” in its narrow sense, but also on those stuck between different systems, including people with long standing health problems and people with facial disfigurement, and study social barriers in their way. In addition to theoretical analysis using game theory and disability studies, we conducted statistical surveys of PwD in cooperation with disability groups and local government, of firms, of patients with long standing health problems. We also conducted statistical survey in foreign countries such as Nepal and Philippines

  • Formation of social structure and communication : Application to economics

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2007.04
    -
    2009.03
     

    ISHIKAWA Ryuichiro

  • Inductive Game Theory and Limited Rationalities : Individual Derivations of Social Views and Behavioral Decision

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research

    Project Year :

    2006.04
    -
    2009.03
     

    KANEKO Mamoru, SUZUKI Nobuyuki, AKIYAMA Eizo, ISHIKAWA Ryuichiro

  • 社会認識の形成とコミュニケーション:その経済学への応用

    日本経済研究奨励財団  奨励金

    Project Year :

    2007.04
    -
    2008.03
     

  • ゲーム理論及び経済理論における認識論的基礎に関する研究

    日本学術振興会  特別研究員奨励費

    Project Year :

    2003.04
    -
    2005.03
     

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Overseas Activities

  • 限定合理的主体の意思決定と意思決定支援のための集合知メカニズムの研究

    2022.09
    -
    2024.09

    フランス   Ecole Polytechnique

Sub-affiliation

  • Faculty of International Research and Education   Graduate School of International Culture and Communication Studies

  • Faculty of Political Science and Economics   Graduate School of Economics

  • Faculty of Commerce   Graduate School of Commerce

  • Faculty of Social Sciences   Graduate School of Social Sciences

Internal Special Research Projects

  • 帰納的学習に基づく集合知メカニズムの情報設計問題:理論・実験・シミュレーション

    2019  

     View Summary

     今年度は、帰納的学習に基づく集合知メカニズムとして、事例ベース意思決定理論を用いた。特にこの理論を顧客の美容室選択のデータ分析に応用し、顧客自身の過去の美容室選択の評価が新しい美容室選択にどのように影響するかを検証した。この分析では、顧客の選択データの価格への感応度が非常に高く、それ以外の要因での説明が困難であった。 この上で、一般的なコミュニケーションの蓄積を通じて、状況認識が変遷する主体を考察するモデルを構築した。このモデルでは、動的認識論理の手法を用いることで、意思決定主体の帰納的学習を多様な選択変数に基づいて構築することが可能にした。今後は行動モデルへの拡張を目指す。

  • 集合知メカニズムにおける情報設計の理論・実験・シミュレーション

    2018  

     View Summary

     本研究では、限定合理的主体が限られた経験の中で、社会をどのように認識するかを考察する。また、そのような主体の認識を補完し、円滑なコミュニケーションや経済活動を促す役割を社会制度が果たすという観点から、適切な制度設計について分析する。 これを進めるために、限定合理的主体が経験を考慮し、自らの意思決定の基準を形成する理論の構築を「事例ベース意思決定理論」に基づいて行った。また、熟議の民主主義などで考察されるコミュニケーションの場を分析するための理論を動的認識論理とメカニズムデザイン理論を用いることで発展させた。

  • 帰納的学習理論に基づく意思決定理論の構築と経済実験への応用

    2017  

     View Summary

     本研究では、経験に基づく新しいゲーム理論である「帰納的ゲーム理論」の理論と実験および哲学的側面について研究を行なった。 理論研究では信念改訂理論を応用し、主体が情報の授受によって直面しているゲームの認識を改訂していく過程を描写する。この研究は次年度以降も続けられる。実験では資産市場実験に応用し、主体の合理性を考察した。特に将来の市場価格の予想の確信レベルと取引行動の関係を考察した。 経験に基づく世界観の形成は、20世紀には論理実証主義を掲げるウィーン学団が考察を行なっている。そのため、本研究との関係を哲学的な側面から考察し、「論理実証主義からみる帰納的ゲーム理論」としてまとめた。

  • 金融市場における投資家の期待形成と金融危機抑制のための銀行規制に関する研究

    2016  

     View Summary

        本研究では、資産取引実験を通じて実際の取引データを収集・分析した。特に注目した実験設定は以下である。1: 過去の実験設定より取引期間(回数)を大幅に増やしたとき、これまでの実験で観察された性質が観察できるか。すなわち、その性質は頑健か2: 中央銀行の量的緩和政策が資産価格バブルの抑制に有効か    1 については、これまでの性質の頑健さが示された一方、フラット・バブルというこれまでとは異なる現象が観察された。2については、中央銀行が国債市場で国債を買い取る量的緩和政策が高い価格を維持することになり、中央銀行による国債販売は資産価格を抑制することが観察され、量的緩和政策の一定の有効性を確認することができた。