Robust Estimation in Finite Mixture Models

Fuente: arXiv
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Auteur principal: Lecestre, Alexandre
Format: Preprint
Publié: 2021
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author Lecestre, Alexandre
author_facet Lecestre, Alexandre
contents We observe a $n$-sample, the distribution of which is assumed to belong, or at least to be close enough, to a given mixture model. We propose an estimator of this distribution that belongs to our model and possesses some robustness properties with respect to a possible misspecification of it. We establish a non-asymptotic deviation bound for the Hellinger distance between the target distribution and its estimator when the model consists of a mixture of densities that belong to VC-subgraph classes. Under suitable assumptions and when the mixture model is well-specified, we derive risk bounds for the parameters of the mixture. Finally, we design a statistical procedure that allows us to select from the data the number of components as well as suitable models for each of the densities that are involved in the mixture. These models are chosen among a collection of candidate ones and we show that our selection rule combined with our estimation strategy result in an estimator which satisfies an oracle-type inequality.
format Preprint
id arxiv_https___arxiv_org_abs_2107_00587
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Robust Estimation in Finite Mixture Models
Lecestre, Alexandre
Statistics Theory
62G05, 62G35, 62F35 (Primary) 62G07 (Secondary)
We observe a $n$-sample, the distribution of which is assumed to belong, or at least to be close enough, to a given mixture model. We propose an estimator of this distribution that belongs to our model and possesses some robustness properties with respect to a possible misspecification of it. We establish a non-asymptotic deviation bound for the Hellinger distance between the target distribution and its estimator when the model consists of a mixture of densities that belong to VC-subgraph classes. Under suitable assumptions and when the mixture model is well-specified, we derive risk bounds for the parameters of the mixture. Finally, we design a statistical procedure that allows us to select from the data the number of components as well as suitable models for each of the densities that are involved in the mixture. These models are chosen among a collection of candidate ones and we show that our selection rule combined with our estimation strategy result in an estimator which satisfies an oracle-type inequality.
title Robust Estimation in Finite Mixture Models
topic Statistics Theory
62G05, 62G35, 62F35 (Primary) 62G07 (Secondary)
url https://arxiv.org/abs/2107.00587