• Corpus ID: 248987521

The Role of Placebo Samples in Observational Studies

  title={The Role of Placebo Samples in Observational Studies},
  author={Ting Ye and Shuxiao Chen and Bo Zhang},
In an observational study, it is common to leverage known null effect to detect bias. One such strategy is to set aside a placebo sample – a subset of data immune from the hypothesized cause-and-effect relationship. Existence of an effect in the placebo sample raises concern of unmeasured confounding bias while absence of it corroborates the causal conclusion. This paper establishes a formal framework for using a placebo sample to detect and remove bias. We state identification assumption, and… 

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