Uncertainty quantification in high dimensional model selection and inference for regression

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Abstract/Contents

Abstract
Recent advances in $ell_1$-regularization methods have proved to be very useful for high dimensional model selection and inference. In the high dimensional regression context, the lasso and its extensions have been successfully employed to identify parsimonious sets of predictors It is well known that the lasso has the advantage of performing model selection and estimation simultaneously. It is less well understood how much uncertainty the lasso estimates may have due to small sample sizes. To model this uncertainty, we present a method, called the "contour Bayesian lasso" for the purposes of constructing joint credible regions for regression parameters. The contour Bayesian lasso is an extension of a recent approach called the "Bayesian lasso" which in turn is based on the Bayesian interpretation of the lasso. The Bayesian lasso uses a Gibbs sampler to generate from the Bayesian lasso posterior and is thus a convenient approach for quantifying uncertainty of lasso estimates. We give theoretical results regarding the optimality of the contour approach, study posterior consistency and the convergence of the Gibbs sampler. We also analyze the frequentist properties of the Bayesian lasso approach. A theoretical analysis of how the convergence of the Gibbs sampler depends on the dimensionality and sample size is undertaken. Our methodology is also illustrated on simulated and real data. We demonstrate that our posterior credible method has good coverage, and thus yields more accurate sparse solutions when the sample size is small. Real life examples are given for the South African prostate cancer data and the diabetes data set.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2012
Issuance monographic
Language English

Creators/Contributors

Associated with Hu, Juegang
Associated with Stanford University, Department of Statistics
Primary advisor Rajaratnam, Balakanapathy
Thesis advisor Rajaratnam, Balakanapathy
Thesis advisor Efron, Bradley
Thesis advisor Johnstone, Iain
Thesis advisor Romano, Joseph P, 1960-
Advisor Efron, Bradley
Advisor Johnstone, Iain
Advisor Romano, Joseph P, 1960-

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Victor Hu.
Note Submitted to the Department of Statistics.
Thesis Thesis (Ph.D.)--Stanford University, 2012.
Location electronic resource

Access conditions

Copyright
© 2012 by Juegang Hu

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