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SHIMIZU Takashi
Graduate School of Economics / Division of Economics
Professor

Researcher basic information

■ Research Keyword
  • 組織の経済学
  • サーチ理論
  • ゲーム理論
  • ミクロ経済学

Research activity information

■ Paper
■ Books And Other Publications
  • Search Theory: The Economics of Decentralized Trade
    Ryoichi Imai, Noritaka Kudoh, Masaru Sasaki, Takashi Shimizu
    Joint work, University of Tokyo Press, Oct. 2007, Japanese
    Scholarly book

  • 『情報社会を理解するキーワード１』国領二郎他（編），「貨幣・価格」，「信用」の項を執筆
    培風館, 2003

  • 貨幣のサーチ・モデル
    日本評論社・経済セミナー, 2002

  • 海外論文Survey10 情報構造と協力関係の維持可能性
    日本評論社・経済セミナー, 1998

  • 海外論文 Survey６ 交渉における合意の形成要因
    日本評論社・経済セミナー, 1997

  • 海外論文Survey２ 不完全な契約下における投資行動
    日本評論社・経済セミナー, 1997

■ Lectures, oral presentations, etc.
  • On the Combination of Biased Members
    Takashi Shimizu
    75th European Meeting of the Econometric Society, Aug. 2023, English
    Oral presentation

  • On the Monetary Exchange in Dynamic Auction Markets with Fiat Money: An Experimental Approach
    Takashi Shimizu
    The 2021 International Workshop for Lab and Field Experiments, Mar. 2021, English
    Oral presentation

  • Equilibrium Selection in Monetary Search Models: An Experimental Approach
    Takashi Shimizu
    The 23rd Experimental Social Science Conference, Nov. 2019
    [Invited]

  • How to Really Open the Door: An Economic Analysis on the Risk of Voice
    SHIMIZU Takashi
    The 2nd Japanese-German Workshop on Contracts and Incentives, Sep. 2019, English, International conference
    [Invited]
    Invited oral presentation

  • Equilibrium Selection in Monetary Search Models: An Experimental Approach
    KAMIYA Kazuya, KOBAYASHI Hajime, SHICHIJO Tatsuhiro, SHIMIZU Takashi
    2018 Asia Pacific Economic Science Association Conference, Feb. 2018, English, Asia Pacific Economic Science Association Conference, Brisbane, Australia, International conference
    Oral presentation

  • Equilibrium Selection in Monetary Search Models: An Experimental Approach
    SHIMIZU TAKASHI
    Japanese Economic Association, 2017 Spring Meeting, Jun. 2017, Japanese, Ritsumeikan University, Domestic conference
    Oral presentation

  • Equilibrium Selection in Monetary Search Models: An Experimental Approach
    KAMIYA Kazuya, KOBAYASHI Hajime, SHICHIJO Tatsuhiro, SHIMIZU Takashi
    North American ESA Conference 2016, Nov. 2016, English, North American ESA Conference, Tucson, Arizona, International conference
    Oral presentation

  • Equilibrium Selection in Monetary Search Models: An Experimental Approach
    SHIMIZU TAKASHI
    Economic Science Association, 2016 North American Meeting, Nov. 2016, English, University of Arizona, International conference
    Oral presentation

  • Equilibrium Selection in Monetary Search Models: An Experimental Approach
    SHIMIZU TAKASHI
    2016 Asian Meeting of the Econometric Society, Aug. 2016, English, Doshisha University, International conference
    Oral presentation

  • Equilibrium Selection in Monetary Search Models: An Experimental Approach
    SHIMIZU TAKASHI
    The Osaka Workshop on Economics of Institutions and Organizations, Tokyo Conference, 2016 Spring, Mar. 2016, English, University of Tokyo, International conference
    Oral presentation

  • Equilibrium Selection in Monetary Search Models: An Experimental Approach
    SHIMIZU TAKASHI
    Summer Workshop in Economic Theory, Aug. 2015, Japanese, Otaru university of commerce, Domestic conference
    Oral presentation

  • Can More Information Facilitate communication?
    Takashi Shimizu
    Econometric Society European Meeting, Aug. 2013, English, University of Gothenburg, Sweden, International conference
    Oral presentation

  • Can More Information Facilitate Communication?
    SHIMIZU TAKASHI
    The 17th Decentralization Conference, Sep. 2011, Japanese, Tsukuba University, Domestic conference
    Oral presentation

  • Can More Information Facilitate Communication?
    SHIMIZU TAKASHI
    Contract Theory Workshop East, Mini-Conference on Cheap Talk and Communication, Dec. 2010, Japanese, Hitotsubashi University, Domestic conference
    Oral presentation

  • Cheap Talk with an Exit Option: A Model of Exit and Voice
    Takashi Shimizu
    The 21th Stony Brook Game Theory Festival, International Conference on Game Theory, Aug. 2010, English, State University of New York at Stony Brook, International conference
    Oral presentation

  • Dynamic Auction Markets with Fiat Money
    Takashi Shimizu
    Search Theory Workshop, Mar. 2010, English, New York University, US, International conference
    Oral presentation

  • Cheap Talk with an Exit Option: A Model of Exit and Voice
    The 21st Stony Brook Game Theory Festival, International Conference on Game Theory, 2010

  • Cheap Talk with an Exit Option: A Model of Exit and Voice
    第21回ゲーム・セオリー・ソサエティ・ストーニー・ブルック・ゲーム理論フェスティバル, 2010

  • Dynamic Auction Markets with Fiat Money
    Takashi Shimizu
    Search and Matching Workshop, Jan. 2010, English, University of Pennsylavania, US, International conference
    Oral presentation

  • Cheap Talk with an Exit Option: A Model of Exit and Voice
    Takashi Shimizu
    Hitotsubashi University Game Theory Workshop 2009, Mar. 2009, Japanese, Hitotsubashi University, Domestic conference
    Oral presentation

  • A Dynamic General Equilibrium Model with Centralized Auction Markets
    Takashi Shimizu
    Japanese Economic Association 2006 Spring Meeting, Jun. 2006, Japanese, 福島大学, Domestic conference
    Oral presentation

  • A Dynamic General Equilibrium Model with Centralized Auction Markets
    Takashi Shimizu
    The 11th Decentralization Conference, Sep. 2005, Japanese, Hosei University, Domestic conference
    Oral presentation

  • Tax-Subsidy Schemes in Money Search Models
    Takashi Shimizu
    Japanese Economic Association 2004 Autumn Meeting, Sep. 2004, Japanese, Okayama University, Domestic conference
    Oral presentation

  • Real Indeterminacy of Stationary Equilibria in Matching Models with Media of Exchange
    Takashi Shimizu
    Japanese Economic Association 2003 Autumn Meeting, Oct. 2003, Japanese, Meiji University, Domestic conference
    Oral presentation

  • Real Indeterminacy of Stationary Equilibria in Matching Models with Media of Exchange
    Takashi Shimizu
    The 8th Decentralization Conference, Oct. 2002, Japanese, Hiroshima University, Domestic conference
    Oral presentation

  • A Theory of Money with Market Places
    Takashi Shimizu
    The Far Eastern Meeting of Econometric Society 2001, Jul. 2001, English, Kobe University, International conference
    Oral presentation

  • A Theory of Money with Market Places
    Takashi Shimizu
    The 6th Decentralization Conference, Sep. 2000, Japanese, Osaka Prefecture Universtiy, Domestic conference
    Oral presentation

  • Procedural Rationality, Nash Equilibrium, and Focal Points
    Takashi Shimizu
    Japan Association of Economics and Econometrics 1997Annual Meeting, Sep. 1997, Japanese, Waseda University, Domestic conference
    Oral presentation

  • Procedural Rationality, Nash Equilibrium, and Focal Points
    Takashi Shimizu, Hirokazu Takizawa
    The 17th Arne Ryde Symposium "Focal Points: Coordination, Complexity and Communication in Strategic Contexts", Aug. 1997, English, Lund University, Sweden, International conference
    Oral presentation

  • Procedural Rationality, Nash Equilibrium, and Focal Points
    東京経済研究センター・サマー・コンファレンス, 1997

  • Learning and Teaching in Games
    Takashi Shimizu
    Japan Association of Economics and Econometrics 1996 Annual Meeting, Sep. 1996, Japanese, Osaka University, Domestic conference
    Oral presentation

■ Affiliated Academic Society
  • Econometric Society

  • American Economic Association

  • 日本経済学会

■ Works
  • 対談『コンピュータの「思考過程」と人間の思考過程』
    2007

■ Research Themes
  • 貨幣モデルにおける財政・金融政策：実験によるアプローチ
    神谷 和也, 小林 創, 七條 達弘, 清水 崇
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Kobe University, Apr. 2021 - Mar. 2026

  • An Economic Analysis on the Voice in Organizations
    清水 崇
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Kobe University, Apr. 2020 - Mar. 2024
    論文「退出と発言の相互作用について」を公刊した。この論文では筆者の既存論文"Cheap Talk with an Exit Option: The Case of Discrete Action Space"、"Cheap Talk with an Exit Option: A Model of Exit and Voice"、および"A Model of Costly Voice"を統合かつ発展させる形で、「発言」と「退出」との間の相互作用を、特に「発言」の費用の種類の分類に基づいて分析した。より具体的には、部下から上司への情報伝達活動を「発言」と捉え、部下の「退出」オプションの存在が「発言」に与える影響を分析した。その結果、上司が部下の退出を恐れているときは退出が発言を促進する可能性がみられる一方、そうでない場合には、逆に退出が発言を阻害する結果も往々にして起きるということが明らかになった。
    また論文"On the Cpmbination of Biased Members"を作成した。この論文では筆者の既存論文"Which Is Better for the Receiver between Senders with Like Biases and Senders with Opposing Biases? "を発展させる形で、部下の「発言」を引き出すための最適な部下の組み合わせについて分析した。より具体的には、各部下は組織の行動を組織全体の最適な水準から乖離させるバイアスを持つ状況を想定する。さらに各部下のバイアスの方向性は皆が知っているが、具体的なバイアスの大きさは各部下の指摘情報であるとする。このとき、異なったバイアスの方向性を持つ部下を組み合わせる異質的な組織よりも、全員が同じ方向のバイアスを持つ同質的な組織の方が、より効率的な「発言」を引き出すことが可能であることを示した。これは、同質的な組織では、自分の誤情報が他の同僚のの誤情報により増幅され組織全体を重大な危機に陥れる可能性を恐れ、それぞれの部下が適切な「発言」を行うよう規律付けられることに起因している。

  • 情報伝達の経済理論・実験分析と国際研究ネットワーク形成
    河村 耕平, 清水 崇, 本領 崇一, 三浦 慎太郎, 定兼 仁
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Waseda University, Apr. 2019 - Mar. 2023
    ２０１９年度は国内ワークショプは予定通り開催できたものの、当該年度に計画されていた２件の海外研究者招聘によるワークショップ開催は、１件は招聘研究者の家庭の事情により、もう１件は新型コロナウィルスの影響により中止となり、更に２０２０年度においても旅行制限により招聘を実施することができなかった。そこで２０２１年度から海外在住の研究者によるオンライン研究会を定期開催し、合わせてインフォーマルな研究交流の機会を設けた。その結果、研究代表者や研究分担者の研究に資する、多くのフィードバックを得ることができた。
    こうしたフィードバックをもとに、研究代表者はメディアとオンラインテクノロジーの動学チープトーク分析を深化させ、新たな厚生分析を加えることで、オンラインニュースへのアクセスのコストが（ネットニュースの充実等により）低くなるほど、ニュース記事の情報の信頼性が低下し、読者の厚生が低下する可能性を示した。また、逐次的コンサルテーションのチープトークモデルに取り組み、情報の受け手が複数の専門家を逐次的に訪れる際には、その訪問順序をランダムにすることにコミットすることにより、専門家同士の利害による情報の操作を抑え、結果として情報の受け手はより多くの情報を得られることを示した。
    この間の研究分担者による研究成果としては、コロナウイルスのような特異な現象が発生した際に政府が情報を秘匿する要因の研究、組織におけるメンバーの退出と発言の相互作用についての研究、インフォーマルな権限委譲（エンパワメント）が部下からの情報伝達を阻害する状況についての研究、チープトークゲームにおいて金銭授受の可能性があれば支払条件等にコミットでき「なくても」均衡における情報伝達量を増やすことを示す研究、が挙げられる。

  • Determinants of prices in search models of money: theory and experiment
    Kamiya Kazuya
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Kobe University, Apr. 2016 - Mar. 2021
    In this study, we clarified what equilibria and prices subjects would choose by conducting economic experiments using random matching models with divisible money, where there is a continuum of stationary equilibria. More specifically, the experiment was conducted under the following different conditions and we analyzed the results: 1. changes in the basic setup (amounts of money and distributions of money holdings in the beginning), 2. changes in monetary policy (various patterns of money injection), and 3. various economic environments (other than random matching). We obtain several results. Among them, the important one is that the efficiency of monetary transactions is higher in the case of divisible money than in the case of indivisible money. Asymmetric properties are also obtained when the amount of money is increased or decreased.

  • 清水 崇
    学術研究助成基金助成金／基盤研究(C), Apr. 2017 - Mar. 2020, Principal investigator
    Competitive research funding

  • KAMIYA KAZUYA
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Grant-in-Aid for Challenging Exploratory Research, Kobe University, Apr. 2016 - Mar. 2019
    Money plays an important role in the modern economy. However, when transaction motives using search model are introduced into the model, there often exists an infinite number of stationary equilibria. Therefore, it is difficult to know which one is chosen. In addition, the effects of a policy, such as a monetary policy, become indeterminate because it is not known which equilibrium is chosen. In this study, we constructed a monetary search model in which the equilibrium is determined without any ad hoc assumptions. In addition, we presented a condition that the equilibrium becomes infinite and a condition that becomes finite.

  • Itoh Hideshi, KOJIMA Kenta, MORIYA Fumitoshi, MUROOKA Takeshi, KAWAMURA Kohei, SANO Ryuji, HORI Kazumi, DAIDO Kohei, NAKAMURA Tomoya, SHIMIZU Takashi, MIURA Shintaro, ISHIHARA Akifumi
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), Grant-in-Aid for Scientific Research (A), Apr. 2013 - Mar. 2018
    We contributed to the development of basic and applied research in the field of contract theory and organizational economics (2016 Nobel Prize in Economic Sciences was awarded to two contributors in this field) and the formation of inter-university research network at the level of the international standard, through the following workshops, conferences, and academic presentations: (1) Regular forty workshops (CTW) during the five years, including sixteen talks by researchers from abroad; (2) Summer conferences held every August; (3) International conferences joint with Taiwan, Hong Kong, and other Asian and Pacific nations held every December; (4) Workshops (CTWE) held in Tokyo, including twelve talks by researchers from abroad; and (5) Forty-seven academic presentations and interactions at domestic and international conferences and thirty-one academic articles.

  • 清水 崇
    学術研究助成基金助成金／基盤研究(C), Apr. 2014 - Mar. 2017, Principal investigator
    Competitive research funding

  • Analysis of the Monetary Policy by Experimental Approach
    Kazuya Kamiya
    Nomura Foundation, 研究助成, 2015 - 2017, Coinvestigator

  • Determinants of Price in Monetary Economy: Theory and Experiment
    Zengin Foundation, 研究助成, 2015 - 2016, Principal investigator

  • NAKABAYASHI Masaki, ISHIGURO Shingo, TAKII Katsuya, OWAN Hideo, MATSUMURA Toshihiro, TANAKA Ryuichi, ISHIDA Junichiro, SASAKI Dan, ISHIBASHI Ikuo, YAMAMOTO Kazuhiro, HORII Ryo, HASHINO Tomoko, SHIMIZU Takashi, TANAKA Wataru, OHDOI Ryoji, NAKAMURA Naofumi, ISHII Rieko, KITAMURA Hiroshi, TAKATSUKI Yasuo, KAWAKA Keisuke, YUKI Takenobu, SAKAI Mayo, MORI Tomoharu, INOMATA Kentaro
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), Grant-in-Aid for Scientific Research (A), The University of Tokyo, Apr. 2010 - Mar. 2015
    We have studied function of internal labor markets, with special attention to interaction between the firm organization and the product and labor markets. Theoretically, we have placed organizational economics in the context of economics of market, and inserted dynamic factors, to scrutinize historical implication of path-dependency. Empirically, we have shown that the deepening of internal labor market practice was consistent to flexible labor market in the 1920-70s by a micro data set, and that, in the national level, internal labor market practices have structurally diminished since the 1990s. Our research provides a viewpoint to consider possible and better work organizations for the future beyond a organizational model very specific to Japan in the 1980s and in a general context.

  • SHIMIZU Takashi
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Kansai University, 2011 - 2013
    As for the monetary theory, I obtained several results regarding the robustness of the real indeterminacy of stationary equilibria in search models of money and the analysis of non-stationary equilibria. As for the communication theory, I obtained several results regarding the analysis of the exit-voice approach, the effect of receiver's private information on communication, and communication among multiple senders. On the other hand, I failed to make a huge progress in the analysis unifying money and communication.

  • 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
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Creative Scientific Research, Grant-in-Aid for Creative Scientific Research, The University of Tokyo, 2007 - 2011
    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.

  • IMAI Ryoichi, KUDOH Noritaka, SASAKI Masaru, SHIMIZU Takashi
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Kyushu University, 2007 - 2009
    We have hosted the Search Theory Workshop, where many leading researchers within and outside Japan have presented their original works. The Workshop has grown as one of the leading research workshops of economic theory.

  • NAKABAYASHI Masaki
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), Grant-in-Aid for Scientific Research (A), 2006 - 2009
    This project has pursued to clarify both empirically and theoretically how modern, or "impersonal," governance of trades that supports market economy has been formed and how firm organization and production organization has developed along with the market expansion. The project leader and the cooperative members have progressed their own portions, and met at monthly "Workshop on Economics of Institutions and Organizations" at Graduate School of Economics, Osaka University, to share each progress. Given that continued effort, in 2009, the last year of this project, first, we held the Tokyo Conference on Economics of Institutions and Organizations in August, with additional financial support by JSPS as an international meeting. Second, also in August, we organized the "Session J7-States, institutions, and development : Standardization and enforcement of trades in diverse markets," in the 15^ World Economic History Congress at University of Utrecht, the Netherlands. Third, we held a panel titled "Institutions, organizations, and market : arbitrage of difference in the market and creation of difference in the organization" in the 78^ annual meeting of Socio-Economic History Society. The "Tokyo Conference" intensively discussed the achievement of this project with concentrating on theoretical aspects. In the World Economic History Congress, the biggest academic meeting of economic history in the world held every 3 years, economic historians of this project provided their works from this project at a session exclusively for this project and exchanged with forefront researchers in the field. In the socio-economic history society meeting, younger members presented their unique works from the project. At all of these opportunities, we have made effort to create new insight about governance of trades that supports market mechanism and its interaction with firm organization and production organization, based both on theoretical and empirical works.

  • SHIMIZU Takashi
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Grant-in-Aid for Young Scientists (B), Kansai University, 2006 - 2008
    動学的環境における市場メカニズムの分析をゲーム理論の手法を用いて行った.特に,(1)名目貨幣が存在するときの動学的市場における均衡の実物的非決定性,(2)「退出」と「発言」の枠組みをモデルとして構築し,市場環境での機能を分析,(3)「仮説形成的推論」を定式化し新たな社会的モデルの分析道具を構築した.

  • Non-Walrasian Price Mechanism : Theory and Applications
    IMAI Ryoichi, KUDOH Noritaka, SASAKI Masaru, SHIMIZU Takashi
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), KYUSHU UNIVERSITY, 2004 - 2005
    This project aims at the following three goals. (1)We maintain monthly research meetings on the search theory and its applications. We regularly invite two speakers including our research team members to present and discuss their new research works. (2)We publish single and/or joint research papers to explore the frontier of the search theory. (3)We write a book which surveys the frontier of the search theory. (1)We have invited leading researchers in search theory form both inside and outside of Japan. They are listed in our main report, and on the website of STW, http://homepage3.nifty.com/ronten/STW.htm. The presenters include Professor Nobuhiro KIYOTAKI of Princeton University and Professor Ricardo Lagos of New York University, who are leading researchers in this field. (2)We have published articles listed in the second page. The issues varied across many research interests. One is the theoretical research of labor market institutions in a search-theoretic model. Second, there are works on monetary economics in the light of both traditional macroeconomics and the search theory. Third, there are works to search for microfoundations of money, especially in the case that there is no constraint on money holdings. (3)We will publish a research survey book on the research frontiers of search theory as well as our own contributions to this field in Japanese. We are now writing chapters of the book, which is supposed to be titled as "Search Theory and Its Applications".

  • 経済システムにおける情報の伝達・蓄積過程の研究
    清水 崇
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Grant-in-Aid for Young Scientists (B), 2003 - 2005
    "On the Role of Tax-Subsidy Scheme in Money Search Models"(神谷和也氏との共著)を改訂した(現在International Economic Review誌に改訂要求後再投稿中).この論文では,研究成果欄記載の"Real Indeterminacy of Stationary Equilibria in Matching Models with Divisible Money"で貨幣の探索モデル(search model of money)において厚生水準が異なる無数の定常均衡が存在すること(「定常均衡の実物的非決定性」("Real Inderterminacy of Stationary Equilibria"))が示されたことを受けて,ある種の「課税-補助金政策」(tax-subsidy scheme)が任意の定常均衡を局所一意的に近似することを示した.すなわち,「課税-補助金政策」は経済を安定的にするとともに,望ましい状態へ誘導することが可能であることを示した. また"Existence of Equilibria in Marching Models of Money : A New Technique"(神谷和也氏との共著)を改訂した(現在Economic Theory誌に改訂要求後再投稿中).この論文では,研究成果欄記載"Real Indeterminacy of Stationary Equilibria in Matching Models with Divisible Money"の結果を利用することにより、貨幣の探索モデルでの貨幣均衡の存在を示す新しい手法を提案した.研究成果欄記載の"On the Existence of Single-Price Equilibria in a Matching Model with Divisible Money and Production Cost"はこの手法をZhou (1999)のモデルに応用した結果である. また"A Dynamic General Equililbrium Model with Centralized Auction Markets"(神谷和也氏との共著)を作成した(現在投稿準備中).この論文では,貨幣の探索モデルの分析で得られた定常均衡の実物的非決定性が中央集権的なオークション市場にも拡張されることを示した.この結果は,従来の一般均衡市場の基礎についての研究において無視されてきた経済の動学的側面およびそこでの貨幣の機能に着目することによって得られた結果である. また現在"Game Theory in Hypothetical Induction"(松井彰彦氏との共著)を作成中である.この論文では,通常のゲーム理論で想定される各プレーヤーが客観的モデルを知っているという仮定を外し、彼らが自分の経験から仮説形成的に主観的モデルを構築していくような状況を考察し,どのような戦略的状況・経験の下で客観的世界を主観的モデルとして復元できるかを分析している.

  • 経済制度の実証分析と設計
    藤原 正寛, 井堀 利宏, 土居 丈朗, 柳川 範之, 神谷 和也, 岡崎 哲二, 清水 崇, 松井 彰彦
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas, Grant-in-Aid for Scientific Research on Priority Areas, The University of Tokyo, 2000 - 2005
    次のような研究を行った。 1.中央から地方政府への補助金に伴うソフトな予算制約(SBC)を、両政府間で課税ベースが重複する2期間モデルを使って分析した。中央政府の国民厚生最大化行動を予想する地方政府は、予め行う過大な支出によって事後的な追加的補助金を引出そうとする。 ハードな予算制約とSBCのどちらが望ましいかは自明でないが、SBCが地方の過大支出と経済厚生負担をもたらす可能性が高いという理論的結果。SBCが過大支出をもたらし経済低迷に結びついた可能性や、地方政府が地方債を過剰発行した実態。政治経済学的背景として、90年代の民間経済活動の低迷が国の補助金獲得の金銭的便益を増加させ、それを巡る政治的圧力がSBCを増大させたなどの実証的結果を得た。 2.90年代に多発した問題解決の先送りを、関係者間のコスト負担交渉に要する時間として分析した。安定的な長期関係があれば関係者間の慣行が負担割合を決めるが、長期関係が崩壊すると新たな制度配置が確立するまで負担原則のフォーカル・ポイントが確立されず、先送りが起こることを消耗戦ゲームの進化動学を使って示した。この結果は、関係者数が増えまた交渉の透明性が低いほど高まるので、全員一致を前提し密室交渉の多い日本に整合的である。 3.見知らぬ人同士でも信頼関係を作り出すための仕組みを、中途解消可能な繰返しPDゲームをランダムにマッチしてプレイする進化動学で分析した。信頼破りの社会的制裁として、新たな相手を容易に見つけられない(失業)、新たな相手と何期か信頼形成投資をする必要があるという周知の仕組みに加えて、異なる信頼形成期間の慣行が社会で共存することが安定になり、ミスマッチによる損失が社会的制裁になる可能性を示した。

  • Theory and applications of societal games : inductive game theory, equilibrium selection, and monetary economies
    MATSUI Akihiko, KAMIYA Kazuya, SHIMIZU Takashi
    Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), The University of Tokyo, 2002 - 2004
    Matsui published a book called "Economics of conventions and norms," (in Japanese) which studies societal games and inductive games. The book received an award called "Nikkei Keizai Tosho-Bunka Sho". A chapter of the book, which studies interaction of cultures, has been published in the Journal of the Japanese and International Economies. The work that studies a mechanism through which conventions last beyond individuals has been published in the Review of Economic Design. Also, we started experimental economics in order to understand the theory better. To be concrete, Matsui conducted experimental studies with graduate students on the economic effects of "voice", publishing two papers in "Keizai-gaku Ronshu", the journal published by the University of Tokyo. In these experiments, we show that in a dictator game, in which "voice" does not matter economically, "voice" of the recipient of the claim and the third party greatly matters. The study of bounded rational players playing a game is an important building block for this series of works, and we have shown some development in this front, too. As part of the fruit in this direction, two papers have been accepted for publication, one in the Journal of Economic Theory and the other in the Japanese Economic Review. The study on search theoretic models of money shows a good progress. The joint work of Matsui and Shimizu has been published in the International Economic Review, so has the work of Kamiya. Shimizu has published "the new development of search theoretic models of money" in Keizaigaku-Kenkyu of Hitotsubashi University. The joint work of Kamiya and Shimizu showed some success and some of their works are under review in some journals.

  • 貨幣のミクロ的基礎理論とその応用
    Akihiko Matsui, Takashi Shimizu
    Zengin Foundation for Studies on Economics and Finance, grant-in-aid from Zengin Foundation for Studies on Economics and Finance, 2000 - 2001

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