Journal Article Biased estimates of treatment effect in randomized experiments with nonlinear regressions and omitted covariates Get access M. H. GAIL, M. H. GAIL Biometry Branch of the Division of Cancer Prevention and Control, National Cancer InstituteBethesda, Maryland, U.S.A. Search for other works by this author on: Oxford Academic Google Scholar S. WIEAND, S. WIEAND Department of Mathematics and Statistics, University of PittsburghPittsburgh, Pennsylvania, U.S.A. Search for other works by this author on: Oxford Academic Google Scholar S. PIANTADOSI S. PIANTADOSI Biometry Branch of the Division of Cancer Prevention and Control, National Cancer InstituteBethesda, Maryland, U.S.A. Search for other works by this author on: Oxford Academic Google Scholar Biometrika, Volume 71, Issue 3, December 1984, Pages 431–444, https://doi.org/10.1093/biomet/71.3.431 Published: 01 December 1984 Article history Received: 01 December 1983 Revision received: 01 April 1984 Published: 01 December 1984
Gail et al. (1984) studied this question.