Benchmark Priors Revisited On Adaptive Shrinkage and the Supermodel Effect in Bayesian Model Averaging

Default prior choices fixing Zellner's g are predominant in the Bayesian Model Averaging literature, but tend to concentrate posterior mass on a tiny set of models. The paper demonstrates this supermodel effect and proposes to address it by a hyper-g prior, whose data-dependent shrinkage adapts...

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Bibliographic Details
Main Author: Feldkircher, Martin
Other Authors: Zeugner, Stefan
Format: eBook
Language:English
Published: Washington, D.C. International Monetary Fund 2009
Series:IMF Working Papers
Online Access:
Collection: International Monetary Fund - Collection details see MPG.ReNa
Description
Summary:Default prior choices fixing Zellner's g are predominant in the Bayesian Model Averaging literature, but tend to concentrate posterior mass on a tiny set of models. The paper demonstrates this supermodel effect and proposes to address it by a hyper-g prior, whose data-dependent shrinkage adapts posterior model distributions to data quality. Analytically, existing work on the hyper-g-prior is complemented by posterior expressions essential to fully Bayesian analysis and to sound numerical implementation. A simulation experiment illustrates the implications for posterior inference. Furthermore, an application to determinants of economic growth identifies several covariates whose robustness differs considerably from previous results
Physical Description:39 pages
ISBN:9781451873498