경향점수를 활용한 인과효과 추정 방법 비교1) : 대응, 가중, 층화, 이중경향점수 보정

Abstract

This study aimed to introduce the double propensity score adjustment method and compare it with matching, weighting, and subclassification methods using estimated propensity scores. Based on empirical data analysis, the study emphasized the recognition of the estmand (ATT vs ATE) a researcher wants to investigate, considering the data structure, the sample sizes of the treatment and comparison groups, and the distributions of covariates between the groups to draw a valid and meaningful inference with respect to the effect of a treatment on the population of interest. To do so, we compared the results of four different propensity score utilization methods by analyzing the effects of private education on mathematic achievement with Gyeonggi educational longitudinal research data(GEPS2012). The results showed that matching was relatively limited to use when the sample size of the comparison group was not large enough or the distributions of propensity score between the treament and comparison groups were not sufficiently overlapped. On the other hand, the double propensity score adjustment method could be useful to estimate the average treatment effect for the treated when research targeted a special population and the treatment and comparison groups were different in various aspects.