Leverage analysis for linear mixed models

We consider a generalized leverage matrix useful for the identification of influential units and observations in linear mixed models and show how a decomposition of this matrix may be employed to identify high leverage points for both the marginal fitted values and the random effect component of the conditional fitted values. We illustrate the different uses of the two components of the decomposition with a simulated example as well as with a real data set.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)