Bayesian Regularized Regression Based on Composite Quantile Method

(整期优先)网络出版时间:2016-02-12
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Recently,variableselectionbasedonpenalizedregressionmethodshasreceivedagreatdealofattention,mostlythroughfrequentist'smodels.ThispaperinvestigatesregularizationregressionfromBayesianperspective.OurnewmethodextendstheBayesianLassoregression(ParkandCasella,2008)throughreplacingtheleastsquarelossandLassopenaltybycompositequantilelossfunctionandadaptiveLassopenalty,whichallowsdifferentpenalizationparametersfordifferentregressioncoefficients.BasedontheBayesianhierarchicalmodelframework,anefficientGibbssamplerisderivedtosimulatetheparametersfromposteriordistributions.Furthermore,westudytheBayesiancompositequantileregressionwithadaptivegroupLassopenalty.Thedistinguishingcharacteristicofthenewlyproposedmethodiscompletelydataadaptivewithoutrequiringpriorknowledgeoftheerrordistribution.Extensivesimulationsandtworealdataexamplesareusedtoexaminethegoodperformanceoftheproposedmethod.Allresultsconfirmthatournovelmethodhasbothrobustnessandhighefficiencyandoftenoutperformsotherapproaches.