We consider forecasting and prequential (predictive sequential) validation of meta-elliptical distributions with time varying parameters. Using the weak prequential principle of Dawid, we conduct model validation avoiding nuisance parameters problems. Results rely on the structure of...

This paper derives the matrix-variate distribution of an arbitrary non-singular linear transformation of Studentized multivariate observations. The joint distributions of the major commonly utilized Studentized versions of (multivariate) regression residuals are obtained as special cases of the...

Sufficient dimension reduction aims at finding transformations of predictor X without losing any regression information of Y versus X. If we are only interested in the information contained in the mean function or the kth moment function of Y given X, estimation of the central mean space or the...

This paper studies weak exogeneity of conditioning variables for the inference of a subset of parameters of the conditional student's t and elliptical linear regression models considered by Spanos (1994). Weak exogeneity of the conditioning variables is shown to hold for the inference of...

We study a portfolio selection model based on Kataoka's safety-first criterion (KSF model in short). We assume that the market is complete but without risk-free asset, and that the returns are jointly elliptically distributed. With these assumptions, we provide an explicit analytical optimal...