방법 비교

	정책 평가 역확률 가중치 (Policy Evaluation Inverse Probability Weighting)	역확률 가중치 (Inverse Probability Weighting, IPW / IPTW)
분야	인과추론	인과추론
계열	Regression model	Regression model
기원 연도	1952 (IPW origin); 2000s (policy evaluation application)	2000
창시자	Horvitz & Thompson (1952); extended to causal policy settings by Robins, Hernan & Brumback (2000) and Imbens & Wooldridge (2009)	Robins, Hernán & Brumback
유형	Reweighting estimator for causal policy analysis	Causal inference weighting estimator
원전	Imbens, G. W., & Wooldridge, J. M. (2009). Recent Developments in the Econometrics of Program Evaluation. Journal of Economic Literature, 47(1), 5-86.	Robins, J. M., Hernán, M. A., & Brumback, B. (2000). Marginal Structural Models and Causal Inference in Epidemiology. Epidemiology, 11(5), 550-560.
별칭	IPW policy evaluation, propensity-weighted policy analysis, inverse probability of treatment weighting	IPW, IPTW, inverse probability of treatment weighting, marginal structural model weighting
관련	6	5
요약	Policy evaluation inverse probability weighting (IPW) uses estimated propensity scores to reweight observed units so that the weighted sample mimics a randomised experiment. Each unit is weighted by the inverse of its probability of receiving the policy, creating a pseudo-population in which treatment assignment is independent of observed covariates and the average treatment effect (ATE) can be read off directly.	Inverse Probability Weighting is a causal-inference method that assigns each observation a weight equal to the inverse of its probability of receiving the treatment it actually received. Introduced by Robins, Hernán and Brumback (2000) for marginal structural models, it builds a pseudo-population in which treatment is independent of measured confounders, balancing selection bias.