Hafner, Christian M.; Reznikova, Olga - In: Computational Statistics & Data Analysis 56 (2012) 11, pp. 3533-3545
of the reasons for the bias lies in an ill-conditioned sample covariance matrix, which is used in the so-called variance … shrinkage to target methods for the sample covariance matrix. Alternatively, the identity matrix, a single factor model, and …