2023年8月の研究業績
OSIPP基幹講座教員の8月の研究業績をご紹介します。 ・松林哲也 先生 ・髙田陽奈子 先生・片桐梓 先生 ・二羽秀和 先生・室岡健志 先生 松林哲也（著書）『何が投票率を高めるのか』有斐閣（2023年8月）https://www.yuhikaku.co.jp/books/detail/9784641149472 概要：期日前投票期間や投票所の数、選挙啓発活動や議員定数の不均衡などの投票環境条件に注目し、それらがどのように投票率に影響を与えているのかを実証的に論じており、日本の有権者を対象とした投票率についての最新の研究成果をわかりやすく解説した。 Hinako Takata（論文）“Separation of Powers in a Globalized Democratic Society: Theorizing the Human Rights Treaty Organs’ Interactions with Various State Organs,” Global Constitutionalism (2023) 1–30. （査読有） https://doi.org/10.1017/S2045381723000114※この論文は、大阪大学の助成により、オープンアクセスとして公開されています。 Abstract：As part of their continuous effort to enhance the effectiveness and democratic legitimacy of human rights treaties, human rights treaty organs have increasingly fostered a direct relationship with various state organs, thereby penetrating the ‘states’ that traditionally have been treated as monolithic legal entities. Treaty organs review the decision-making process of each type of state organ – courts, parliaments and administrative organs – and make remedial orders that are substantially addressed to specific state organs. Such phenomena go hand in hand with the relativization of the distinction between the legal spheres in which human rights treaty organs and state organs operate. This is the first study to address such phenomena as a totality. It constructs the ‘separation of powers in a globalized democratic society’ theory, thereby proposing how each type of state organ and the treaty organs should interact under human rights treaties. Its findings contribute, first, to the harmonious achievement of the effectiveness and democratic legitimacy of human rights treaties; second, to the reform of the classical paradigm of international law, in which monolithic states are the only relevant legal entities; and third, to the long-standing debates on the relationship between international and national laws from a new angle. Azusa Katagiri（論文）”Revisiting the puzzle of endogenous nuclear proliferation” Journal of Peace Research（査読有） https://journals.sagepub.com/doi/10.1177/00223433231177727 Abstract：Nuclear proliferation literature typically differentiates supply-side and demand-side factors influencing the spread of nuclear weapons. These distinct approaches to the proliferation puzzle raise the following empirical questions: Does nuclear supply stimulate states’ demand for nuclear weapons? Conversely, does the demand for nuclear weapons really facilitate the acquisition of nuclear supply? If such endogeneity exists between the demand-side and supply-side determinants, how would it cause empirical bias in the estimation of their effects on nuclear proliferation? This article aims to unpack endogenous mechanisms of nuclear demand and nuclear supply over the course of nuclear proliferation. In particular, it examines two potential sources of endogeneity: (1) simultaneous interactions between states’ nuclear development decisions and nuclear technological capability and (2) selection bias in nuclear development. To address each source of endogeneity, simultaneous equation models and the duration models with selection are estimated, respectively. Contrary to what recent supply-side literature suggests, the empirical analyses reveal that states’ nuclear demand is primarily driven by external security threats instead of their existing nuclear technology, and that their successful acquisition of nuclear technology mainly follows as the result of nuclear development efforts but does not necessarily depend on individual supply-side factors. This article addresses the typical inference issues in nuclear proliferation research and contributes to our synthetic understanding of proliferation mechanisms. 二羽秀和（その他の記事）「長期国債買い入れにはどのような効果があるのか」『週刊東洋経済』東洋経済新報社2023年8/26第7131号 概要：日本銀行は、2013年4月から、2%インフレ目標を達成するために量的・質的金融緩和政策を実施している。この間、日本銀行は、日銀当座預金と引き換えに大量の長期国債を購入してきた。本稿では、中央銀行の長期国債買入れの効果について、マクロ経済理論の観点から検討する。とくに、物価水準の財政理論に基づいて議論する。同理論は、貨幣経済理論の１つであり、政府債務の持続可能性の問題がインフレ率の決定に及ぼす影響について考察するものである。 Takeshi Murooka coauthored with Yuichi Yamamoto（Discussion Paper）“Higher-Order Misspecification and Equilibrium Stability” DP-2023-E-002 (August 2, 2023) https://www.osipp.osaka-u.ac.jp/archives/DP/2023/DP2023E002.pdf Abstract：This paper considers a Bayesian learning problem where strategic players jointly learn an unknown economic state, and show that one’s higher-order misspecification (i.e., one’s misspecification about the opponent’s misspecification) can have a significant impact on the equilibrium outcome. We consider a simple environmental problem where players’ production, as well as an unknown state, affects the quality of the environment. Crucially, we assume that one of the players is unrealistically optimistic about the quality of the environment. When this optimism is common knowledge, the equilibrium outcome is continuous in the amount of optimism, and hence small optimism leads to approximately correct learning of the state. In contrast, when the optimism is not common knowledge and each player is unaware of the opponent having a different view about the world, the equilibrium outcome is discontinuous, and even vanishingly small optimism leads to completely incorrect learning. We then analyze a general Bayesian learning model and discuss when such discontinuity arises.
