@misc{Sailer2009exact,
abstract = {The analysis of crossover designs assuming i.i.d. errors leads to biased variance estimates whenever the true covariance structure is not spherical. As a result, the OLS F-Test for treatment differences is not valid. Bellavance et al. (Biometrics 52:607-612, 1996) use simulations to show that a modified F-Test based on an estimate of the within subjects covariance matrix allows for nearly unbiased tests. Kunert and Utzig (JRSS B 55:919-927, 1993) propose an alternative test that does not need an estimate of the covariance matrix. However, for designs with more than three observations per subject Kunert and Utzig (1993) only give a rough upper bound for the worst-case variance bias. This may lead to overly conservative tests. In this paper we derive an exact upper limit for the variance bias due to carry-over for an arbitrary number of observations per subject. The result holds for a certain class of highly efficient carry-over balanced designs.},
address = {Dortmund},
author = {Oliver Sailer},
copyright = {http://www.econstor.eu/dspace/Nutzungsbedingungen},
keywords = {310; bias; correlated errors; crossover designs; fixed effects model; upper limit; variance estimation},
language = {eng},
number = {2009,01},
publisher = {Univ., SFB 475},
series = {Technical Report // Sonderforschungsbereich 475, Komplexit\"{a}tsreduktion in Multivariaten Datenstrukturen, Universit\"{a}t Dortmund},
title = {An exact upper limit for the variance bias in the carry-over model with correlated errors},
url = {http://hdl.handle.net/10419/36579},
year = {2009}
}