The Future Strikes Back: Using Future Treatments to Detect and Reduce Hidden Bias.

ABSTRACT: Conventional advice discourages controlling for postoutcome variables in regression analysis. By contrast, we show that controlling for commonly available postoutcome (i.e., future) values of the treatment variable can help detect, reduce, and even remove omitted variable bias (unobserved confounding). The premise is that the same unobserved confounder that affects treatment also affects the future value of the treatment. Future treatments thus proxy for the unmeasured confounder, and researchers can exploit these proxy measures productively. We establish several new results: Regarding a commonly assumed data-generating process involving future treatments, we (1) introduce a simple new approach and show that it strictly reduces bias, (2) elaborate on existing approaches and show that they

SUBMITTER: Elwert F 

PROVIDER: S-EPMC9398191 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature