Machine Learning, Causal Inference, Meta Learning, Instruments, Observational Studies.
estimator of ATE is defined as (see A Survey on Causal Inference): where n denotes the sample size, ê(x) is the estimated propensity score given features x, Tᵢ is the treatment assignment for iᵗʰ unit, and Yᵢ denotes the observed outcome for iᵗʰ unit. Theoretical results show that adjustment for