방법 비교

	다기간 매칭 추정량	Coarsened Exact Matching (CEM)
분야	인과추론	인과추론
계열	Regression model	Regression model
기원 연도	2005	2011-2012
창시자	Abadie (2005); Imbens & Wooldridge (2009)	Iacus, King, & Porro
유형	Quasi-experimental / causal inference	Matching / causal inference
원전	Abadie, A. (2005). Semiparametric Difference-in-Differences Estimators. Review of Economic Studies, 72(1), 1-19.	Iacus, S. M., King, G., & Porro, G. (2012). Causal Inference without Balance Checking: Coarsened Exact Matching. Political Analysis, 20(1), 1-24.
별칭	panel matching estimator, longitudinal matching, multi-wave matching, repeated-cross-section matching	CEM, coarsened matching, monotonic imbalance bounding matching
관련	6	6
요약	The multi-period matching estimator extends the standard matching framework to settings with multiple time periods, pairing each treated unit to similar untreated units based on pre-treatment covariates or propensity scores, then using within-pair before-after differences to estimate the average treatment effect on the treated (ATT). Leveraging repeated observations, it simultaneously controls for observed confounders and time-invariant unobserved heterogeneity.	Coarsened Exact Matching is a preprocessing method that achieves covariate balance by temporarily coarsening continuous variables into bins, exactly matching treated and control units within those bins, and then discarding all unmatched units. Introduced by Iacus, King, and Porro (2011, 2012), it bounds imbalance on each covariate independently, yielding a matched sample on which any estimator can be applied without relying on a propensity score model.