On importance sampling and independent Metropolis-Hastings with an unbounded weight function

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Deligiannidis, George, Jacob, Pierre E., Khribch, El Mahdi, Wang, Guanyang
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866908407518199808
author Deligiannidis, George
Jacob, Pierre E.
Khribch, El Mahdi
Wang, Guanyang
author_facet Deligiannidis, George
Jacob, Pierre E.
Khribch, El Mahdi
Wang, Guanyang
contents Importance sampling and independent Metropolis-Hastings (IMH) are among the fundamental building blocks of Monte Carlo methods. Both require a proposal distribution that globally approximates the target distribution. The Radon-Nikodym derivative of the target distribution relative to the proposal is called the weight function. Under the assumption that the weight is unbounded but has finite moments under the proposal distribution, we study the approximation error of importance sampling and of the particle independent Metropolis-Hastings algorithm (PIMH), which includes IMH as a special case. For the chains generated by such algorithms, we show that the common random numbers coupling is maximal. Using that coupling we derive bounds on the total variation distance of a PIMH chain to its target distribution. Our results allow a formal comparison of the finite-time biases of importance sampling and IMH, and we find the latter to be have a smaller bias. We further consider bias removal techniques using couplings, and provide conditions under which the resulting unbiased estimators have finite moments. These unbiased estimators provide an alternative to self-normalized importance sampling, implementable in the same settings. We compare their asymptotic efficiency as the number of particles goes to infinity, and consider their use in robust mean estimation techniques.
format Preprint
id arxiv_https___arxiv_org_abs_2411_09514
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On importance sampling and independent Metropolis-Hastings with an unbounded weight function
Deligiannidis, George
Jacob, Pierre E.
Khribch, El Mahdi
Wang, Guanyang
Statistics Theory
Methodology
Importance sampling and independent Metropolis-Hastings (IMH) are among the fundamental building blocks of Monte Carlo methods. Both require a proposal distribution that globally approximates the target distribution. The Radon-Nikodym derivative of the target distribution relative to the proposal is called the weight function. Under the assumption that the weight is unbounded but has finite moments under the proposal distribution, we study the approximation error of importance sampling and of the particle independent Metropolis-Hastings algorithm (PIMH), which includes IMH as a special case. For the chains generated by such algorithms, we show that the common random numbers coupling is maximal. Using that coupling we derive bounds on the total variation distance of a PIMH chain to its target distribution. Our results allow a formal comparison of the finite-time biases of importance sampling and IMH, and we find the latter to be have a smaller bias. We further consider bias removal techniques using couplings, and provide conditions under which the resulting unbiased estimators have finite moments. These unbiased estimators provide an alternative to self-normalized importance sampling, implementable in the same settings. We compare their asymptotic efficiency as the number of particles goes to infinity, and consider their use in robust mean estimation techniques.
title On importance sampling and independent Metropolis-Hastings with an unbounded weight function
topic Statistics Theory
Methodology
url https://arxiv.org/abs/2411.09514