近期重要研究成果

Testing Identifying Assumptions in Fuzzy Regression Discontinuity Designs (with Yoichi Arai, Toru Kitagawa, Ismael Mourifié, and Yuanyuan Wan, accepted by QUANTITATIVE ECONOMICS)

作者 Yoichi Arai
許育進
Toru Kitagawa
Ismael Mourifié
宛圓淵
摘要 We propose a new specification test for assessing the validity of fuzzy regression discon-tinuity designs (FRD-validity). We derive a new set of testable implications, characterized by a set ofinequality restrictions on the joint distribution of observed outcomes and treatment status at the cut-off. We show that this new characterization exploits all the information in the data useful for detectingviolations of FRD-validity. Our approach differs from, and complements existing approaches that testcontinuity of the distributions of running variables and baseline covariates at the cut-off since oursfocuses on the distribution of the observed outcome and treatment status. We show that the proposedtest has appealing statistical properties. It controls size in large sample uniformly over a large class ofdistributions, is consistent against all fixed alternatives, and has non-trivial power against some localalternatives. We apply our test to evaluate the validity of two FRD designs. The test does not reject the FRD-validity in the class size design studied by Angrist and Lavy (1999) and rejects in the insurancesubsidy design for poor households in Colombia studied by Miller, Pinto, and Vera-Hernández (2013) for some outcome variables, while existing density tests suggest the opposite in each of the cases.