Berk, Richard; Pitkin, Emil; Brown, Lawrence; Buja, Andreas - In: Evaluation Review 37 (2013) 3-4, pp. 170-196
Background:It has become common practice to analyze randomized experiments using linear regression with covariates. Improved precision of treatment effect estimates is the usual motivation. In a series of important articles, David Freedman showed that this approach can be badly flawed. Recent...