|
|
Department of Statistics, The Ohio State University
Statistics and Biostatistics Colloquium Series
High Dimensional Predictive Densities
Xinyi Xu
Department of Statistics
The Wharton School
University of Pennsylvania
3:30PM - Tuesday, February 15, 2005
Room 170, Eighteenth Avenue Bldg. (EA 170)
ABSTRACT
Commonly used statistical approaches to prediction provide a single
number as a forecast of an unknown future quantity, sometimes
attaching an error bound to convey the uncertainty of the
prediction. A more comprehensive approach to prediction provides a
complete predictive estimate that assigns probabilities to every
possible outcome that may occur. Because they are more comprehensive,
such descriptions of uncertainty lead to better decision making and
sharper assessment of risks. In this talk, the problem of estimating
the predictive density of a multivariate normal variable under
Kullback-Leibler loss is considered. We show that there exist broad
classes of formal Bayes rules, including Bayes rules under
superharmonic priors, which dominate the best invariant minimax
estimator for this problem. We also show that the class of generalized
Bayes estimators is a complete class, and obtain sufficient conditions
for the admissibility of formal Bayes rules. Fundamental similarities
and differences with the parallel theory of estimating a multivariate
normal mean under quadratic loss are described throughout.
Meet the speaker in Room 212 Cockins Hall at 4:30 p.m. Refreshments will be served.
|