Yukio Koriyama

Yukio Koriyama is a Professor of Economics (Professeur de classe exceptionnelle) at École Polytechnique and a Visiting Professor at Waseda University.

Born in Osaka in 1974, he attended Nada Junior and Senior High School before earning his B.S. in Mathematics and M.S. in Mathematical Sciences from the University of Tokyo. He graduated from École Polytechnique (X97), where his exposure to game theory led him to transition from mathematics to economics. He earned his Ph.D. in Economics from the University of Chicago in 2008 under the supervision of Nobel laureate Roger Myerson. He has been on the faculty of École Polytechnique since 2008.

His research focuses on collective decision-making theory, utilizing game theory, experimental economics, and behavioral economics to analyze social institutions, with a particular emphasis on voting theory and participatory budgeting.

Having lived in France, the United States, China, and South Africa, and having visited 76 countries and regions, he draws on a global perspective to advance the theory and practice of democratic decision-making. In addition to his academic work, he enjoys street performance with the mathematician and juggler Peter Frankl and has performed on the street in 38 countries. [Instagram]

He is the author of several books, including "Collective Decision Making and EBPM -- Preventing the Tyranny of the Majority" (Nikkei Publishing) and introductory books on mathematical problem-solving for youth. Edited "One Hundred Years of Game Theory: A Nobel Symposium" (2026), Cambridge University Press, with Mark Voorneveld, Jörgen Weibull, Tommy Andersson, Roger B. Myerson, Jean-François Laslier, Rida Laraki.

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郡山幸雄（こおりやまゆきお）

エコール・ポリテクニーク経済学部教授（Professeur de classe exceptionelle）。早稲田大学訪問教授。1974年大阪生まれ。灘中学・灘高等学校、東京大学理学部数学科、同大学院数理学研究科修士課程修了。エコール・ポリテクニーク卒業（X97）。フランス留学中にゲーム理論に出会い、数学から経済学に転向する。シカゴ大学ではRoger Myerson（2007年ノーベル賞）教授指導のもと2008年経済学博士号取得。同年よりエコール・ポリテクニーク経済学部にて教鞭を取る。

専門は集団的意思決定理論で、ゲーム理論、実験経済学、行動経済学を用いて社会的意思決定メカニズムの分析、とくに投票理論、参加型予算等の研究に取り組む。フランス、アメリカの他中国、南アフリカに在住経験があり、76の国と地域に滞在した経験を活かして、広い視野を持ってより良い民主的意思決定理論の発展と実践を目指す。趣味の大道芸ではピーター・フランクル氏に師事し、これまで38カ国で芸を披露した。[Instagram]

著書に「多数派の専横を防ぐ意思決定理論とEBPM（日本経済新聞出版）」「パズル気分で算数オリンピック（講談社）」「親子でめざせ算数オリンピック（講談社）」など。編著に"One Hundred Years of Game Theory: A Nobel Symposium" (Cambridge University Press, Mark Voorneveld, Jörgen Weibull, Tommy Andersson, Roger B. Myerson, Jean-François Laslier, Rida Larakiと共編、chapter 27 執筆)。