{ "id": "2102.12976", "version": "v1", "published": "2021-02-24T05:09:41.000Z", "updated": "2021-02-24T05:09:41.000Z", "title": "A Hybrid Approximation to the Marginal Likelihood", "authors": [ "Eric Chuu", "Debdeep Pati", "Anirban Bhattacharya" ], "categories": [ "stat.CO", "stat.ME" ], "abstract": "Computing the marginal likelihood or evidence is one of the core challenges in Bayesian analysis. While there are many established methods for estimating this quantity, they predominantly rely on using a large number of posterior samples obtained from a Markov Chain Monte Carlo (MCMC) algorithm. As the dimension of the parameter space increases, however, many of these methods become prohibitively slow and potentially inaccurate. In this paper, we propose a novel method in which we use the MCMC samples to learn a high probability partition of the parameter space and then form a deterministic approximation over each of these partition sets. This two-step procedure, which constitutes both a probabilistic and a deterministic component, is termed a Hybrid approximation to the marginal likelihood. We demonstrate its versatility in a plethora of examples with varying dimension and sample size, and we also highlight the Hybrid approximation's effectiveness in situations where there is either a limited number or only approximate MCMC samples available.", "revisions": [ { "version": "v1", "updated": "2021-02-24T05:09:41.000Z" } ], "analyses": { "keywords": [ "marginal likelihood", "markov chain monte carlo", "approximate mcmc samples", "parameter space increases", "high probability partition" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }