Sampling‐based Randomised Designs for Causal Inference under the Potential Outcomes Framework

Summary We establish the inferential properties of the mean‐difference estimator for the average treatment effect in randomised experiments where each unit in a population is randomised to one of two treatments and then units within treatment groups are randomly sampled. The properties of this estimator are well understood in the experimental design scenario where first units are randomly sampled and then treatment is randomly assigned but not...