Estimation under the matrix variate elliptical model
DOI:
https://doi.org/10.37920/sasj.2016.50.1.7Keywords:
Bayesian inference, Bessel function of matrix argument, Characteristic matrix, Matrix variate elliptical model, Maximum posterior mode, Normal-inverseWishart, normal-Wishart, Squared error lossAbstract
The problem of estimation within the matrix variate elliptical model is addressed. In this paper a subjective Bayesian approach is followed to derive new estimators for the parameters of the matrix variate elliptical model by assuming the previously intractable normal-Wishart prior. These new estimators are compared to the estimators derived under a normal-inverse Wishart prior as well as the objective Jeffreys’ prior which results in the maximum likelihood estimators, using different measures. A valuable contribution is the development of algorithms for the simulation of the posterior distributions of the matrix variate parameters with emphasis on the new proposed estimators. A simulation study as well as Fisher’s Iris data set are used to illustrate the novelty of these new estimators and to investigate the accuracy gained by assuming the normal-Wishart prior.