title: Principal stratification--a goal or a tool?
abstract: Principal stratification has recently become a popular tool to address certain causal inference questions, particularly in dealing with post-randomization factors in randomized trials. Here, we analyze the conceptual basis for this framework and invite response to clarify the value of principal stratification in estimating causal effects of interest.
authors.affiliation: University of California, Los Angeles, USA.
authors.forename: Judea
authors.initials: J
authors.lastname: Pearl
mesh_terms: D015984:Causality; D006801:Humans; D015233:Models, Statistical; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D012107:Research Design