Bayesian nonparametric modeling of latent partitions via Stirling-gamma priors

Fuente: arXiv
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Autores principales: Zito, Alessandro, Rigon, Tommaso, Dunson, David B.
Formato: Preprint
Publicado: 2023
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author Zito, Alessandro
Rigon, Tommaso
Dunson, David B.
author_facet Zito, Alessandro
Rigon, Tommaso
Dunson, David B.
contents Dirichlet process mixtures are particularly sensitive to the value of the precision parameter controlling the behavior of the latent partition. Randomization of the precision through a prior distribution is a common solution, which leads to more robust inferential procedures. However, existing prior choices do not allow for transparent elicitation, due to the lack of analytical results. We introduce and investigate a novel prior for the Dirichlet process precision, the Stirling-gamma distribution. We study the distributional properties of the induced random partition, with an emphasis on the number of clusters. Our theoretical investigation clarifies the reasons of the improved robustness properties of the proposed prior. Moreover, we show that, under specific choices of its hyperparameters, the Stirling-gamma distribution is conjugate to the random partition of a Dirichlet process. We illustrate with an ecological application the usefulness of our approach for the detection of communities of ant workers.
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id arxiv_https___arxiv_org_abs_2306_02360
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Bayesian nonparametric modeling of latent partitions via Stirling-gamma priors
Zito, Alessandro
Rigon, Tommaso
Dunson, David B.
Methodology
Statistics Theory
Dirichlet process mixtures are particularly sensitive to the value of the precision parameter controlling the behavior of the latent partition. Randomization of the precision through a prior distribution is a common solution, which leads to more robust inferential procedures. However, existing prior choices do not allow for transparent elicitation, due to the lack of analytical results. We introduce and investigate a novel prior for the Dirichlet process precision, the Stirling-gamma distribution. We study the distributional properties of the induced random partition, with an emphasis on the number of clusters. Our theoretical investigation clarifies the reasons of the improved robustness properties of the proposed prior. Moreover, we show that, under specific choices of its hyperparameters, the Stirling-gamma distribution is conjugate to the random partition of a Dirichlet process. We illustrate with an ecological application the usefulness of our approach for the detection of communities of ant workers.
title Bayesian nonparametric modeling of latent partitions via Stirling-gamma priors
topic Methodology
Statistics Theory
url https://arxiv.org/abs/2306.02360