Propensity Score Matching - Statpower

IntroductionModeling the CovariatesSubclassificationMatchingBalancing ScoresThe Propensity ScoreMatching MethodsUsing Propensity Scores – A General StrategyAn ExampleKey QuestionsDefinition of a Propensity ScoreKey AssumptionMathematical PropertiesKey ImplicationsKey QuestionsPropensity scores have some nice properties that, in principle,seem to solve a very vexing problem. However, before jumpingon the very large propensity score bandwagon, we need to recall1 The propensity score is a parameter, i.e., a probability. Wenever know it precisely. We only know sample estimates ofit.2 Propensity scores are guaranteed to yield unbiased causaleffects only if strong ignorability holds.For now, let’s move on to a discussion of the practical aspects ofcalculating and using sample estimates of propensity scores.MultilevelPropensity Score Matching