Consider a model parameterized by u 1⁄4 (c, l), where c is the parameter of interest. The problem of eliminating the nuisance parameter l can be tackled by resorting to a pseudo-likelihood function L*(c) for c—namely, a function of c only and the data y with properties similar to those of a likelihood function. If one treats L*(c) as a true likelihood, the posterior distribution p*(c | y) } p(c)L*(c) for c can be considered, where p(c) is a prior distribution on c. The goal of this article is to construct probability matching priors for a scalar parameter of interest only (i.e., priors for which Bayesian and frequentist inference agree to some order of approximation) to be used in p*(c | y). When L*(c) is a marginal, a conditional, or a modification of the profile likelihood, we show that p(c) is simply proportional to the square root of the inverse of the asymptotic variance of the pseudo-maximum likelihood estimator. The proposed priors are compared with the reference or Jeffreys’ priors in four examples.
Prior distributions from pseudo-likelihoods in the presence of nuisance parameters
CABRAS, STEFANO;RACUGNO, WALTER
2009-01-01
Abstract
Consider a model parameterized by u 1⁄4 (c, l), where c is the parameter of interest. The problem of eliminating the nuisance parameter l can be tackled by resorting to a pseudo-likelihood function L*(c) for c—namely, a function of c only and the data y with properties similar to those of a likelihood function. If one treats L*(c) as a true likelihood, the posterior distribution p*(c | y) } p(c)L*(c) for c can be considered, where p(c) is a prior distribution on c. The goal of this article is to construct probability matching priors for a scalar parameter of interest only (i.e., priors for which Bayesian and frequentist inference agree to some order of approximation) to be used in p*(c | y). When L*(c) is a marginal, a conditional, or a modification of the profile likelihood, we show that p(c) is simply proportional to the square root of the inverse of the asymptotic variance of the pseudo-maximum likelihood estimator. The proposed priors are compared with the reference or Jeffreys’ priors in four examples.I metadati presenti in IRIS UNICA sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono protetti da diritto d'autore, salvo diversa indicazione.



