New■2025年度　第4回　大阪大学経済学研究会　のご案内（IPP研究会共催）

日時：2025年5月29日（木）13：30～15：00

会場：豊中キャンパスOSIPP棟6階　会議室

講師：国本　隆氏（Singapore Management University）

タイトル：Rationalizable Incentives: Interim Rationalizable Implementation of Correspondences 

アブストラクト：When the normative goals for a set of agents can be summarized in a set-valued rule and agents take actions that are rationalizable, a new theory of incentives emerges in which standard Bayesian incentive compatibility (BIC) is relaxed significantly. The paper studies the interim rationalizable implementation of social choice sets with a Cartesian product structure, a leading example thereof being ex-post efficiency. Setwise incentive compatibility (setwise IC), much weaker than BIC, is shown to be necessary for implementation. Setwise IC enforces incentives flexibly within the entire correspondence, instead of the pointwise enforcement entailed by BIC. Sufficient conditions, while based on the existence of SCFs in the correspondence that make truthful revelation a dominant strategy, are shown to be permissive to allow the implementation of ex-post efficiency in many settings where equilibrium implementation fails (e.g., bilateral trading, multidimensional signals). Furthermore, this success comes at little cost: all our mechanisms are well behaved, in the sense that best responses always exist.

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 Time and Date:  13：30～15：00, Thursday, May, 29th 

 Seminar Venue: The Conference Room (会議室) on the 6th floor of OSSIP棟 in Toyonaka Campus

 Presenters:  Takashi Kunimoto Singapore Management University）

 Title: Rationalizable Incentives: Interim Rationalizable Implementation of Correspondences 

 Abstract: When the normative goals for a set of agents can be summarized in a set-valued rule and agents take actions that are rationalizable, a new theory of incentives emerges in which standard Bayesian incentive compatibility (BIC) is relaxed significantly. The paper studies the interim rationalizable implementation of social choice sets with a Cartesian product structure, a leading example thereof being ex-post efficiency. Setwise incentive compatibility (setwise IC), much weaker than BIC, is shown to be necessary for implementation. Setwise IC enforces incentives flexibly within the entire correspondence, instead of the pointwise enforcement entailed by BIC. Sufficient conditions, while based on the existence of SCFs in the correspondence that make truthful revelation a dominant strategy, are shown to be permissive to allow the implementation of ex-post efficiency in many settings where equilibrium implementation fails (e.g., bilateral trading, multidimensional signals). Furthermore, this success comes at little cost: all our mechanisms are well behaved, in the sense that best responses always exist.

■今後のスケジュール

会場：豊中キャンパスOSIPP棟6階　会議室

講師：Juan Pantano氏（University of Arizona  ）

タイトル：Stochastic Compliance and Identification of Treatment Effects (joint with Hidehiko Ichimura)

アブストラクト：The exclusion restriction plays a key role in the identification of LATE (Imbens & Angrist (1994), Angrist, Imbens & Rubin (1996)). We discuss a particularly ubiquitous way in which the exclusion restriction would seem to be generically violated. We argue that this form of violation is not addressed in the many applications that rely on this influential framework. We characterize the bias that this particular violation gives rise to and, more constructively, discuss how to use the particular structure of the violation along with milder assumptions and additional data to restore identification. We provide sharper bounds by exploiting the specific structure of the exclusion restriction violation we uncover. Further, with an additional assumption which is plausible in many empirical settings, we restore point identification of LATE. We illustrate with examples and discuss why this violation is likely present in most existing empirical applications. We discuss how our arguments naturally extend to other IV settings where the LATE parameter is commonly invoked, such as randomized controlled trials with imperfect compliance and fuzzy regression discontinuity designs. Moving beyond LATE, we also consider how the same problems and solution ideas apply to identification of the MTE profile and more structural "Roy" models of treatment effects.

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日時：2025年6月26日（木）13：30～15：00

会場：豊中キャンパスOSIPP棟6階　会議室

講師：Ali Bakhtawar (Aix-Marseille Shcool of Economics)

タイトル：TBA

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日時：2025年7月31日（木）13：30～15：00

会場：豊中キャンパスOSIPP棟6階　会議室

講師：高橋　裕希(Tilburg University）

タイトル：TBA

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