The propensity score is the conditional probability of exposure to a treatment given observed covariates. In a cohort study, matching or stratifying treated and control subjects on a single variable, the propensity score, tends to balance all of the observed covariates; however, unlike random assignment of treatments, the propensity score may not also balance unobserved covariates. The authors ...

Methods for propensity score analysis (PSA) originated with Rosenbaum and Rubin (1983), as vehicles to sharpen and clarify treatment group comparisons in observational studies. Although highly recommended by many statisticians, and applied often in medical sciences, PSA has seen relatively few applications in the social and behavioral sciences. This paper aims to facilitate sound PSA applicatio...

The propensity score plays a central role in a variety of causal inference settings. In particular, matching and weighting methods based on the estimated propensity score have become increasingly common in the analysis of observational data. Despite their popularity and theoretical appeal, the main practical difficulty of these methods is that the propensity score must be estimated. Researchers...

Compared to high school graduates, adolescents who drop out of school are more likely to have a range of negative outcomes, including lower verbal capacities; however, the true nature of this association is not well-understood. Dropping out of school could have an important effect on reducing verbal skills, or the link between dropping out of school and diminished verbal skills could be a spuri...

In a nonrandomized or observational study, propensity scores may be used to balance observed covariates and trajectory groups may be used to control baseline or pretreatment measures of outcome. The trajectory groups also aid in characterizing classes of subjects for whom no good matches are available and to define substantively interesting groups between which treatment effects may vary. These...

Using recent data from the Chinese manufacturing industry and the generalised propensity score, this paper establishes economically significant causal effects of foreign acquisition on domestic and export markets dynamics. JEL classification: F23, G28, C24

This paper explores the effects of overseas activity on parent firm employment in a panel of Taiwan’s large, listed firms during 2000-2005. Propensity score matching estimates of discrete effects suggest that employment growth did not differ significantly between new parents and firms with no overseas operations. Generalized method of moments’ estimates of marginal effects for all firms indicat...

I provide a simple introduction to the use of propensity score reweighting to assess the effect of changes in covariates on the distribution of an outcome (such as wages). I relate this to the literature on estimating “average treatment effects” and Blinder/Oaxaca decompositions as well as discuss some of the limitations and uses of reweighting.

Comparative-effectiveness research (CER) aims to produce actionable evidence regarding the effectiveness and safety of medical products and interventions as they are used outside of controlled research settings. Although CER evidence regarding medications is particularly needed shortly after market approval, key methodological challenges include (i) potential bias due to channeling of patients ...