Tractable Bayesian variable selection: beyond normality

Harvard | Vancouver

Rossell, D and Rubio, FJ. 2017. Tractable Bayesian variable selection: beyond normality. [Online]. Figshare. Available from: - https://doi.org/10.6084/m9.figshare.5410747.v1

Export Citation

Sharing

Description

Bayesian variable selection often assumes normality, but the effects of model misspecification are not sufficiently understood. There are sound reasons behind this assumption, particularly for large p: ease of interpretation, analytical and computational convenience. More flexible frameworks exist, including semi- or non-parametric models, often at the cost of some tractability. We propose a simple extension that allows for skewness and thicker-than-normal tails but preserves tractability. It leads to easy interpretation and a log-concave likelihood that facilitates optimization and integration. We characterize asymptotically parameter estimation and Bayes factor rates, under certain model misspecification. Under suitable conditions misspecified Bayes factors induce sparsity at the same rates than under the correct model. However, the rates to detect signal change by an exponential factor, often reducing sensitivity. These deficiencies can be ameliorated by inferring the error distribution, a simple strategy that can improve inference substantially. Our work focuses on the likelihood and can be combined with any likelihood penalty or prior, but here we focus on non-local priors to induce extra sparsity and ameliorate finite-sample effects caused by misspecification. We show the importance of considering the likelihood rather than solely the prior, for Bayesian variable selection. The methodology is in R package ‘mombf’.

Published in a 3rd party system Date: 14 September 2017
Data capture method:
Mode of data capture
Simulation
Data Creators(s): Rossell, D and Rubio, FJ
LSHTM Faculty/Department: Faculty of Epidemiology and Population Health > Dept of Non-Communicable Disease Epidemiology
Participating Institutions: London School of Hygiene & Tropical Medicine, London, United Kingdom, Universitat Pompeu Fabra, Barcelona, Spain

Files

Data not available from this repository.

Dataset may be available externally from:

Resources

Actions

Edit Item Edit Item (admin only)