第22回社研・森口賞受賞者

森口賞	岸下大樹 / Daiki Kishishita（東京大学経済学研究科博士課程 / Graduate School of Economics, University of Tokyo)
論文	Contagion of Populist Extremism (with Atsushi Yamagishi)
講評	ポピュリズムがある国からまた別の国へと伝播する現象を理論的に解明する研究である。議論は一国のモデルから始まる。有権者が限られた情報に基づき好ましい政策を実現してくれる政治家を評価する状況では、政治家は自らが腐敗していないことを有権者に示して支持を得るため、敢えて過激な政策を掲げることが示される。次に、議論は各国が逐次的に政治家を選出していくモデルに拡張される。最適政策が国家間で同一なとき、ポピュリズムの伝播が投票者最適マルコフ完全ベイズ均衡として実現し、最初の国が過激な政策をとると伝播が深刻である点、一国でも中庸な政策をとると伝播が直ちに止まるパラダイム転換が起こる点を指摘する。さらに、最適な政策が国家間である程度連動しているならば、ポピュリズムの出現する国が多数を占めるサイクルに陥ることを示す。このように本研究は、エージェンシー問題に起因する社会的学習の失敗によりポピュリズムの伝播と関連現象を包括的に論じている点で極めて高く評価できる。

入選	星紀翔 / Kisho Hoshi（一橋大学経済学研究科修士課程 / Graduate School of Economics, Hitotsubashi University)
論文	Medical Schools, Access to Doctors and Health Outcomes: Evidence from "One Prefecture, One Medical School Policy" in Japan
講評	This paper exploits Japan’s “One Prefecture, One Medical School Policy” (OPOMS) of the 1970’s to estimate the effect of greater access to physicians on health outcomes. First of all, Mr. Hoshi did a commendable job of hand collecting much of the data used in this study, which provides a valuable new resource for health economists going forward. This dataset contains information on the location and start-date of newly established medical schools and university hospitals, as well as information on physicians, hospital characteristics, and mortality rates. This information was used to establish that university hospitals, and the subsequent graduation of medical students, have a positive impact on access to physicians. Second, and most importantly, the study establishes that mortality rates for diseases requiring advanced medical treatments – e.g., cancer and stroke - declined within prefectures affected by the OPOMS. Furthermore, this decline is attributable to the supply of newly-minted medical-school graduates, as opposed to the establishment of university hospitals per-se. As these results are very important from both a scientific and policy perspective, we encourage Mr. Hoshi to do more work establishing the precise mechanism(s) through which the OPOMS affected health outcomes. The work so far had gone a long way in establishing an overall effect, but a more granular analysis – for instance: does geographic dispersion and/or average distance to the university hospital affect outcomes? – would strengthen the study’s overall policy impact.

入選	黒石悠介 / Yusuke Kuroishi (Department of Economics, London School of Economics and Political Science)
論文	The Role of Trademarks in International Trade: Evidence from Chinese Exporters in the African Tyre Industry
講評	This paper investigates the role of trademarks in international trade. The paper extends a Melitz-type heterogeneous firm trade model by incorporating endogenous trademarks and quality choices. The model yields predictions on the effects of a decreasing foreign trademark costs on firm adjustments via the reallocation channel. The model predictions are tested using Chinese exporters’ data in African tire industry. For identification, the paper uses a difference-in-differences approach by exploiting a quasi-natural experiment that the World Intellectual Property Organization (WIPO) recognized the Madrid Protocol, which induces many African countries to sign trademark agreement and join the WIPO in 2015. The empirical findings show that firms with trademarks have higher export unit price, quantity and revenues. Overall, the topic of the paper is important and the empirical results are interesting. It is important to understand how global intellectual property system affects firm product-quality choice, productivity and export-import decision.

2019年12月11日におこなわれた報告会の様子です。