Bayesian Model Averaging in Model-Based Clustering and Density Estimation

Abstract We propose Bayesian model averaging (BMA) as a method for postprocessing the results of model-based clustering. Given a number of competing models, appropriate model summaries are averaged, using the posterior model probabilities, instead of being taken from a single “best” model. We demonstrate the use of BMA in model-based clustering for a number of datasets. We show that BMA provides a useful summary of the clustering of observations while taking model uncertainty into account. Further, we show that BMA in conjunction with model-based clustering gives a competitive method for density estimation in a multivariate setting. Applying BMA in the model-based context is fast and can give enhanced modeling performance. Keywords: Bayesian model averaging · Cluster analysis · Density estimation · High-dimensional data · Model-based clustering · Model uncertainty