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Honest Exploration of Intractable Probability Distributions via Markov Chain Monte Carlo

Statistical SciencePublished 1 November 2001Open access
James P. Hobert, Galin L. Jones
Citations256
SJR quartileQ1
SJR score1.67
SNIP2.24
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TL;DR

The goal of this paper is to demystify the analysis that leads to honest answers to (Q1) and (Q2) and to serve as a bridge between those developing Markov chain theory and practitioners using MCMC to solve practical problems.

Abstract

Two important questions that must be answered whenever a Markov\nchain Monte Carlo (MCMC) algorithm is used are (Q1) What is an appropriate\nburn-in? and (Q2) How long should the sampling continue after\nburn-in?Developing rigorous answers to these questions presently requires a\ndetailed study of the convergence properties of the underlying Markov chain.\nConsequently, in most practical applications of MCMC, exact answers to (Q1)and\n(Q2) are not sought. The goal of this paper is to demystify the analysis that\nleads to honest answers to (Q1) and (Q2). The authors hope that this article\nwill serve as a bridge between those developing Markov chain theory and\npractitioners using MCMC to solve practical problems.\n¶ The ability to address (Q1) and (Q2) formally comes from\nestablishing a drift condition and an associated minorization\ncondition, which together imply that the underlying Markov chain is\ngeometrically ergodic. In this article, we explain exactly what drift\nand minorization are as well as how and why these conditions can be used to\nform rigorous answers to (Q1) and (Q2). The basic ideas are as follows. The\nresults of Rosenthal (1995) and Roberts and Tweedie (1999) allow one to use\ndrift and minorization conditions to construct a formula giving an\nanalytic upper bound on the distance to stationarity. A rigorous answer to (Q1)\ncan be calculated using this formula. The desired characteristics of the target\ndistribution are typically estimated using ergodic averages. Geometric\nergodicity of the underlying Markov chain implies that there are central limit\ntheorems available for ergodic averages (Chan and Geyer 1994). The regenerative\nsimulation technique (Mykland, Tierney and Yu, 1995; Robert, 1995) can be used\nto get a consistent estimate of the variance of the asymptotic normal\ndistribution. Hence, an asymptotic standard error can be calculated, which\nprovides an answer to (Q2) in the sense that an appropriate time to stop\nsampling can be determined. The methods are illustrated using a Gibbs sampler\nfor a Bayesian version of the one-way random effects model and a data set\nconcerning styrene exposure.

Keywords

Computer ScienceMathematics