ON THE CONSTRUCTION OF BAYES MINIMAX ESTIMATORS 1

Bayes estimation of the mean of a multivariate normal distribution is considered under quadratic loss. We show that, when particular spherical priors are used, the superharmonicity of the square root of the marginal density provides a viable method for constructing (possibly proper) Bayes (and admissible) minimax estimators. Examples illustrate the theory; most notably it is shown that a multivariate Student- t prior yields a proper Bayes minimax estimate.

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