Doubly robust (DR) estimators that combine regression adjustments and inverse probability weighting (IPW) are widely used in causal inference with observational data because they are claimed to be consistent when either the outcome or the treatment selection model is correctly specified (Scharfstein et al., 1999). This property of "double…

This paper is based on previous studies in applying propensity score methods to study multiple treatment variables to examine the causal moderator effect. The propensity score methods will be demonstrated in a case study to examine the causal moderator effect, where the moderators are categorical and continuous variables. Moderation analysis is an…

In this paper the authors present a new method for sample selection for scale-up experiments. This method uses propensity score matching methods to create a sample that is similar in composition to a well-defined generalization population. The method they present is flexible and practical in the sense that it identifies units to be targeted for…