手法を比較

	回帰キンクデザイン (RKD)	回帰不連続デザイン（Regression Discontinuity Design, RDD）
分野	因果推論	因果推論
系統	Regression model	Regression model
提唱年	2015	2008
提唱者	Card, Lee, Pei & Weber	Imbens & Lemieux (guide to practice); Cattaneo, Idrobo & Titiunik (practical introduction)
種類	Quasi-experimental design (slope-based RDD)	Quasi-experimental causal design
原典	Card, D., Lee, D. S., Pei, Z. & Weber, A. (2015). Inference on Causal Effects in a Generalized Regression Kink Design. Econometrica, 83(6), 2453-2483.	Imbens, G. W., & Lemieux, T. (2008). Regression Discontinuity Designs: A Guide to Practice. Journal of Econometrics, 142(2), 615-635.
別名	RKD, regression kink design, kink regression discontinuity, Regresyon Kırılma Tasarımı (RKD — Regression Kink Design)	RDD, regression discontinuity design, sharp RDD, fuzzy RDD
関連	4	5
概要	The Regression Kink Design is a quasi-experimental method that estimates a causal effect when a policy rule creates a change in slope (a kink) — rather than a jump — at a known threshold of a running variable. It was formalised as a generalized design by Card, Lee, Pei and Weber (2015) and is the slope-based counterpart of the regression discontinuity design.	Regression Discontinuity Design is a quasi-experimental method that identifies a causal effect by locally comparing units just above and just below a cutoff on a continuous assignment (running) variable. Formalised for applied work by Imbens and Lemieux (2008) and developed as a practical framework by Cattaneo, Idrobo, and Titiunik (2020), it estimates a local average treatment effect (LATE) at the threshold.