de Luna, Xavier; Lundin, Mathias - Institutet för Arbetsmarknads- och Utbildningspolitisk … - 2009
In observational studies, the estimation of a treatment effect on an outcome of interest is often done by controlling on a set of pre-treatment characteristics (covariates). This yields an unbiased estimator of the treatment effect when the assumption of unconfoundedness holds, that is, there...