Power of edge exclusion tests in graphical Gaussian models
1 Departamento de Métodos Quantitativos, ISCTE Business School, Av. Forças Armadas, 1649-026 Lisboa, Portugal fatima.salgueiro{at}iscte.pt, 2 Southampton Statistical Sciences Research Institute, University of Southampton, Southampton SO17 1BJ, U.K. pws{at}socsci.soton.ac.uk, bigmac{at}socsci.soton.ac.uk
Asymptotic multivariate normal approximations to the joint distributions of edge exclusion test statistics for saturated graphical Gaussian models are derived. Non-signed and signed square-root versions of the likelihood ratio, Wald and score test statistics are considered. Noncentral chi-squared approximations are also considered for the non-signed versions. These approximations are used to estimate the power of edge exclusion tests and an example is presented.
Key Words: Likelihood ratio test; Overall power; Partial correlation; Score test; Signed square-root test; Wald test
Received February 2003. Revised June 2004.