Updated on 2024/02/27

写真a

 
KAWAMURA, Kohei
 
Affiliation
Faculty of Political Science and Economics, School of Political Science and Economics
Job title
Professor
Degree
DPhil ( 2007 University of Oxford )

Research Experience

  • 2016
    -
    Now

    Waseda University   Faculty of Political Science and Economics   Professor

  • 2014
    -
    2016

    University of Edinburgh   School of Economics   Senior Lecturer in Economics

  • 2007
    -
    2014

    University of Edinburgh   School of Economics   Lecturer in Economics (テニュア付)

Research Areas

  • Economic theory
 

Papers

  • News credibility and the quest for clicks

    Kohei Kawamura, Mark T. Le Quement

    JOURNAL OF PUBLIC ECONOMICS   227   105005 - 105005  2023.11  [Refereed]

    DOI

    Scopus

  • Strategic central bank communication: Discourse analysis of the Bank of Japan's Monthly Report

    Kawamura Kohei, Kobashi Yohei, Shizume Masato, Ueda Kozo

    JOURNAL OF ECONOMIC DYNAMICS & CONTROL   100   230 - 250  2019.03  [Refereed]

    DOI

    Scopus

    6
    Citation
    (Scopus)
  • Expert information and majority decisions

    Kohei Kawamura, Vasileios Vlaseros

    JOURNAL OF PUBLIC ECONOMICS   147   77 - 88  2017.03  [Refereed]

     View Summary

    This paper shows experimentally that hearing expert opinions can be a double-edged sword for collective decision making. We present a majoritarian voting game of common interest where committee members receive not only private information, but also expert information that is more accurate than private information and observed by all members. In theory, there are Bayesian Nash equilibria where the committee members' voting strategy incorporates both types of information and access to expert information enhances the efficiency of the majority decision. However, in the laboratory, expert information had excessive influence on the voting behaviour and prevented efficient aggregation of individual information. We find a large efficiency loss due to the presence of expert information especially when the committee size is large. Using an incentivized questionnaire, we find that many subjects seVerely underestimate the efficiency gain from information aggregation and they follow expert information Much more frequently than efficiency requires. This suggests that those who understand the efficiency gain from information aggregation and perceive the game correctly might nonetheless be "stuck" in an inefficient outcome. (C) 2017 Elsevier B.V. All rights reserved.

    DOI

    Scopus

    12
    Citation
    (Scopus)
  • Confidence and competence in communication

    Kohei Kawamura

    THEORY AND DECISION   78 ( 2 ) 233 - 259  2015.02  [Refereed]

     View Summary

    This paper studies information transmission between an uninformed decision maker (receiver) and an informed agent (sender) who have asymmetric beliefs ("confidence") on the sender's ability ("competence") to observe the state of nature. We find that even when the material payoffs of the players are perfectly aligned, the sender's over- and underconfidence on his information give rise to information loss in communication, although they do not by themselves completely eliminate information transmission in equilibrium. However, an underconfident sender may prefer no communication to informative communication. We also show that when the sender is biased, overconfidence can lead to more information transmission and welfare improvement.

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • SPILLOVERS OF EQUAL TREATMENT IN WAGE OFFERS

    Kohei Kawamura, Jozsef Sakovics

    SCOTTISH JOURNAL OF POLITICAL ECONOMY   61 ( 5 ) 487 - 501  2014.11  [Refereed]

     View Summary

    We analyse a labour-matching model with wage posting, where - reflecting institutional constraints - firms cannot differentiate their wage offers within certain subsets of workers. Inter alia, we find that the presence of impersonal wage offers leads to wage compression, which propagates to the wages for high productivity workers who receive personalized offers.

    DOI

    Scopus

  • Biasing selection contests with ex-ante identical agents

    Kohei Kawamura, Ines Moreno de Barreda

    ECONOMICS LETTERS   123 ( 2 ) 240 - 243  2014.05  [Refereed]

     View Summary

    This note shows that when the designer of a contest wishes the winner have high ability, she is better off giving a head start to one of the contestants even if they are ex-ante identical. If the contestants are ex-ante asymmetric, the designer should give a head start to the one who is more likely to have high ability. (C) 2014 Elsevier B.V. All rights reserved.

    DOI

    Scopus

    12
    Citation
    (Scopus)
  • Eliciting information from a large population

    Kohei Kawamura

    JOURNAL OF PUBLIC ECONOMICS   103   44 - 54  2013.07  [Refereed]

     View Summary

    This paper studies information transmission in social surveys where a welfare maximizing decision maker communicates with a random sample of individuals from a large population who have heterogeneous preferences. The population distribution of preferences is unknown and has to be estimated, based on answers from the respondents. The decision maker cannot identify the true distribution of preferences even if the sample size becomes arbitrarily large, since the respondents have incentive to "exaggerate" their preferences especially as the sample size becomes larger and each respondent has weaker influence on the decision. The quality of communication with each respondent may improve as the sample size becomes smaller, and thus we identify the trade-off between the quality and quantity of communication. We show that the decision maker may prefer to sample a smaller number of individuals when the prior is weaker. (C) 2013 Elsevier B.V. All rights reserved.

    DOI

    Scopus

    5
    Citation
    (Scopus)
  • A Model of Public Consultation: Why is Binary Communication so Common?

    Kohei Kawamura

    ECONOMIC JOURNAL   121 ( 553 ) 819 - 842  2011.06  [Refereed]

     View Summary

    This article studies information transmission between multiple agents with heterogeneous preferences and a welfare maximising decision maker who chooses the quality or quantity of a public good (e.g. size of a public project; pace of lectures in a classroom; government regulation) that is consumed by all of them. As the number of agents becomes larger, the quality of information transmission diminishes. The use of binary messages (e.g. 'yes or no' ) is shown to be a robust mode of communication even when the preferences and policy space are non-binary.

    DOI

    Scopus

    14
    Citation
    (Scopus)
  • Noisy Talk

    Kohei Kawamura

    THEORETICAL ECONOMICS   2 ( 4 ) 395 - 440  2007.12  [Refereed]

  • Managerial control inside the firm

    Shinichi Hirota, Kohei Kawamura

    JOURNAL OF THE JAPANESE AND INTERNATIONAL ECONOMIES   21 ( 3 ) 324 - 335  2007.09  [Refereed]

     View Summary

    This paper proposes an implicit control mechanism of managers inside the firm. We argue that the need to motivate workers may make it beneficial for a self-interested, short-sighted manager to pursue the long-term viability of a firm. When the firm is in a stable environment, this implicit control mechanism may not contradict shareholder value maximization. However, when the firm needs restructuring, this mechanism diminishes firm value. We discuss when external governance is desirable, and when it is not. Our model also offers economic explanations for some related issues in managerial behavior, such as restructuring aversion, survival motive, and excessive risk aversion.

    DOI

    Scopus

    8
    Citation
    (Scopus)

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Research Projects

  • インクルーシブ社会に向けた消費者保護法制の経済分析

    日本学術振興会  科学研究費助成事業

    Project Year :

    2021.04
    -
    2024.03
     

    新井 泰弘, 河村 耕平

     View Summary

    昨年度はキャンセル料を含んだ最適契約モデルに関する考察を主に行った。事業者の最適キャンセル料設定を考えるにあたり、以下の2点が重要となる。① 消費者は購入段階では商品の品質を完全に判別できない、② 契約の事後的な取消に商品の摩耗や返送のための送料等の取消費用がかかる。こうした取消費用は、消費者の負担割合が小さくなると、購入してみて品質が低かったらすぐ取消をする、という消費者の過剰な取消を招き、社会的に不必要な取消費用の発生と、事業者の円滑な取引の阻害が発生する可能性がある。一方で、消費者の負担割合の増加は消費者側からの取消を抑制してしまう。
    こうした設定の上で、消費者の情報収集を組み込んだモデルを考察している。具体的には、消費者が一定の費用を支払うことで商品の品質に関する情報を集めることが出来るケースの想定である。現実社会においても、我々はインターネット販売や通信販売を利用する際に、サイトに表示されている口コミや販売業者の情報について事前に調べることがある。こうした消費者の情報収集は、望ましくない取引を事前に防ぐ意味でも重要である。また、消費者の情報収集の程度は、もし取引をキャンセルした場合の費用負担に大きく依存しており、事業者の設定するキャンセル料に大きく左右されることになる。そのため、事業者のキャンセル料設定と、その下での消費者の情報収集構造について理論分析を行っている。
    モデルの途中結果については、研究分担者である河村が2022年1月にWINPEC Microeconomics Workshopにて報告しており、現在受け取ったフィードバックを基にモデルの再構築を進めている。

  • 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

    日本学術振興会  科学研究費助成事業

    Project Year :

    2019.04
    -
    2023.03
     

    河村 耕平, 清水 崇, 本領 崇一, 三浦 慎太郎, 定兼 仁

     View Summary

    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。
    <BR>
    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。
    <BR>
    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。

  • チープトークによる内生的複数回コンサルテーションの分析

    日本学術振興会  科学研究費助成事業

    Project Year :

    2017.04
    -
    2020.03
     

    河村 耕平

  • Strategic Behaviour, Bounded Rationality and Subjective Legitimacy in Collective Decision Making

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

    Project Year :

    2016
    -
    2019
     

    KAWAMURA Kohei, Le Quement Mark, Vlaseros Vasileios, Hopkins Ed, Kornienko Tatiana

     View Summary

    Thanks to the Grant, the PI has been able to continue ongoing research with hid collaborators based in Europe smoothly, and newly develop his own researchers network in Japan, as soon as he moved to Tokyo. The research project has primarily focused on information transmission and aggregation, within the context of strategic behaviour in collective decision making. In particular, the PI has published a paper on voting experiment where the presence of both private and public information leads to significant inefficiency; and an empirical paper on strategic communication by a central bank using text analysis and a game theoretic model. The PI also completed papers and gave presentations on the most efficient strategy profile in a standard voting game; game theoretic analysis of the accuracy of media reports on the internet; and a few other theoretical and empirical projects.

  • Economics of Contracts and Organizations

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

    Project Year :

    2013.04
    -
    2018.03
     

    Itoh Hideshi, KOJIMA Kenta, MORIYA Fumitoshi, MUROOKA Takeshi, KAWAMURA Kohei, SANO Ryuji, HORI Kazumi, DAIDO Kohei, NAKAMURA Tomoya, SHIMIZU Takashi, MIURA Shintaro, ISHIHARA Akifumi

     View Summary

    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.

 

Syllabus

 

Sub-affiliation

  • Faculty of Commerce   Graduate School of Commerce

  • Faculty of Social Sciences   Graduate School of Social Sciences

  • Faculty of Commerce   School of Commerce

Research Institute

  • 2019
    -
     

    Research Institute of Business Administration   Concurrent Researcher

Internal Special Research Projects

  • チープトークによる内生的な複数回コンサルテーションの分析

    2016  

     View Summary

    引き続き共同研究者との頻繁なやり取りを通して、基礎モデルの特に3つのセットアップについて分析を進め、1つについて均衡および比較静学の導出を行った。残りの2つにセットアップについては、計算・証明作業を続行中である。