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Main Authors: Ke, Xiongwen, Fan, Yanan
Format: Preprint
Published: 2021
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Online Access:https://arxiv.org/abs/2108.03464
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author Ke, Xiongwen
Fan, Yanan
author_facet Ke, Xiongwen
Fan, Yanan
contents It is well known that Bridge regression enjoys superior theoretical properties when compared to traditional LASSO. However, the current latent variable representation of its Bayesian counterpart, based on the exponential power prior, is computationally expensive in higher dimensions. In this paper, we show that the exponential power prior has a closed form scale mixture of normal decomposition for $α=(\frac{1}{2})^γ, γ\in \{1, 2,\ldots\}$. We call these types of priors $L_{\frac{1}{2}}$ prior for short. We develop an efficient partially collapsed Gibbs sampling scheme for computation using the $L_{\frac{1}{2}}$ prior and study theoretical properties when $p>n$. In addition, we introduce a non-separable Bridge penalty function inspired by the fully Bayesian formulation and a novel, efficient coordinate descent algorithm. We prove the algorithm's convergence and show that the local minimizer from our optimisation algorithm has an oracle property. Finally, simulation studies were carried out to illustrate the performance of the new algorithms. Supplementary materials for this article are available online.
format Preprint
id arxiv_https___arxiv_org_abs_2108_03464
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Bayesian $L_{\frac{1}{2}}$ regression
Ke, Xiongwen
Fan, Yanan
Methodology
Statistics Theory
It is well known that Bridge regression enjoys superior theoretical properties when compared to traditional LASSO. However, the current latent variable representation of its Bayesian counterpart, based on the exponential power prior, is computationally expensive in higher dimensions. In this paper, we show that the exponential power prior has a closed form scale mixture of normal decomposition for $α=(\frac{1}{2})^γ, γ\in \{1, 2,\ldots\}$. We call these types of priors $L_{\frac{1}{2}}$ prior for short. We develop an efficient partially collapsed Gibbs sampling scheme for computation using the $L_{\frac{1}{2}}$ prior and study theoretical properties when $p>n$. In addition, we introduce a non-separable Bridge penalty function inspired by the fully Bayesian formulation and a novel, efficient coordinate descent algorithm. We prove the algorithm's convergence and show that the local minimizer from our optimisation algorithm has an oracle property. Finally, simulation studies were carried out to illustrate the performance of the new algorithms. Supplementary materials for this article are available online.
title Bayesian $L_{\frac{1}{2}}$ regression
topic Methodology
Statistics Theory
url https://arxiv.org/abs/2108.03464