Bayesian Gaussian Copula Factor Models for Mixed Data

Autor: Murray, Jared S., Dunson, David B., Carin, Lawrence, Lucas, Joseph E.
Rok vydání: 2011
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1080/01621459.2012.762328
Popis: Gaussian factor models have proven widely useful for parsimoniously characterizing dependence in multivariate data. There is a rich literature on their extension to mixed categorical and continuous variables, using latent Gaussian variables or through generalized latent trait models acommodating measurements in the exponential family. However, when generalizing to non-Gaussian measured variables the latent variables typically influence both the dependence structure and the form of the marginal distributions, complicating interpretation and introducing artifacts. To address this problem we propose a novel class of Bayesian Gaussian copula factor models which decouple the latent factors from the marginal distributions. A semiparametric specification for the marginals based on the extended rank likelihood yields straightforward implementation and substantial computational gains, critical for scaling to high-dimensional applications. We provide new theoretical and empirical justifications for using this likelihood in Bayesian inference. We propose new default priors for the factor loadings and develop efficient parameter-expanded Gibbs sampling for posterior computation. The methods are evaluated through simulations and applied to a dataset in political science. The methods in this paper are implemented in the R package bfa.
Comment: To appear in JASA Theory & Methods. This revision corrects the simulation study in the previous version (and adds another), adds new figures and edits some of the previous figures, corrects some typographical errors and has been edited for style and length
Databáze: arXiv