Causal Inference, Instrumental Variable, Ab Testing, Encouragement Design, Average Treatment Effect.
treatment-response types from four to two. For example, given that for 20% of subjects the observed values were Z = 1, X = 0, and Y = 0, the following can be deduced: Z = 1 with X = 0 can only occur for never-takers or defiers. X = 0 with Y = 0 can only occur for never-converters or