Yuli Liang: Circular Block Symmetry in Multilevel Models

The aim of this article is to study a multilevel model with a covariance structure that is block circularly symmetric. Models that describe symmetries present in
the error structure of observations have been widely used in dierent applications, with early examples from psychometric and medical research. Useful results are
obtained for the spectrum of these structured matrices. Estimators of mean and variance-covariance parameters are derived.