Biometrika Advance Access published online on August 5, 2007
Biometrika, doi:10.1093/biomet/asm040
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Copyright © 2007 Biometrika Trust
Article |
Integrated likelihood functions for non-Bayesian inference
Department of Statistics, Northwestern University, Evanston, Illinois 60208-4070, U.S.A.
severini{at}northwestern.edu
Received for publication 1 November 2005.
Revision received 1 November 2006.
| Abstract |
|---|
Consider a model with parameter
= (
,
), where
is the parameter of interest, and let L(
,
) denote the likelihood function. One approach to likelihood inference for
is to use an integrated likelihood function, in which
is eliminated from L(
,
) by integrating with respect to a density function
(
|
). The goal of this paper is to consider the problem of selecting
(
|
) so that the resulting integrated likelihood function is useful for non-Bayesian likelihood inference. The desirable properties of an integrated likelihood function are analyzed and these suggest that
(
|
) should be chosen by finding a nuisance parameter
that is unrelated to
and then taking the prior density for
to be independent of
. Such an unrelated parameter is constructed and the resulting integrated likelihood is shown to be closely related to the modified profile likelihood.
Key Words: Modified profile likelihood Nuisance parameter Orthogonal parameters Reference prior