Easily Computed Marginal Likelihoods for Multivariate Mixture Models Using the THAMES Estimator

Fuente: arXiv
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Main Authors: Metodiev, Martin, Irons, Nicholas J., Perrot-Dockès, Marie, Latouche, Pierre, Raftery, Adrian E.
Format: Preprint
Published: 2025
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author Metodiev, Martin
Irons, Nicholas J.
Perrot-Dockès, Marie
Latouche, Pierre
Raftery, Adrian E.
author_facet Metodiev, Martin
Irons, Nicholas J.
Perrot-Dockès, Marie
Latouche, Pierre
Raftery, Adrian E.
contents We present a new version of the truncated harmonic mean estimator (THAMES) for univariate or multivariate mixture models. The estimator computes the marginal likelihood from Markov chain Monte Carlo (MCMC) samples, is consistent, asymptotically normal and of finite variance. In addition, it is invariant to label switching, does not require posterior samples from hidden allocation vectors, and is easily approximated, even for an arbitrarily high number of components. Its computational efficiency is based on an asymptotically optimal ordering of the parameter space, which can in turn be used to provide useful visualisations. We test it in simulation settings where the true marginal likelihood is available analytically. It performs well against state-of-the-art competitors, even in multivariate settings with a high number of components. We demonstrate its utility for inference and model selection on univariate and multivariate data sets.
format Preprint
id arxiv_https___arxiv_org_abs_2504_21812
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Easily Computed Marginal Likelihoods for Multivariate Mixture Models Using the THAMES Estimator
Metodiev, Martin
Irons, Nicholas J.
Perrot-Dockès, Marie
Latouche, Pierre
Raftery, Adrian E.
Methodology
We present a new version of the truncated harmonic mean estimator (THAMES) for univariate or multivariate mixture models. The estimator computes the marginal likelihood from Markov chain Monte Carlo (MCMC) samples, is consistent, asymptotically normal and of finite variance. In addition, it is invariant to label switching, does not require posterior samples from hidden allocation vectors, and is easily approximated, even for an arbitrarily high number of components. Its computational efficiency is based on an asymptotically optimal ordering of the parameter space, which can in turn be used to provide useful visualisations. We test it in simulation settings where the true marginal likelihood is available analytically. It performs well against state-of-the-art competitors, even in multivariate settings with a high number of components. We demonstrate its utility for inference and model selection on univariate and multivariate data sets.
title Easily Computed Marginal Likelihoods for Multivariate Mixture Models Using the THAMES Estimator
topic Methodology
url https://arxiv.org/abs/2504.21812