Causal Inference, Instrumental Variables, Stats 361, Stanford, Data Science.
a treatment group), α is E[Y_i(0)] — the average outcome of a control group, W_i is binary value indicating whether i-th sample is treated or not, τ is ATE value, and finally ε_i is Y_i(0) — E[Y_i(0)] — the residual term of control group. In addition, E[ε_i|W_i=0] because of unconfoundedness