Title
Robustness of Stein-type estimators under a non-scalar error covariance structure
Abstract
The Stein-rule (SR) and positive-part Stein-rule (PSR) estimators are two popular shrinkage techniques used in linear regression, yet very little is known about the robustness of these estimators to the disturbances' deviation from the white noise assumption. Recent studies have shown that the OLS estimator is quite robust, but whether this is so for the SR and PSR estimators is less clear as these estimators also depend on the F statistic which is highly susceptible to covariance misspecification. This study attempts to evaluate the effects of misspecifying the disturbances as white noise on the SR and PSR estimators by a sensitivity analysis. Sensitivity statistics of the SR and PSR estimators are derived and their properties are analyzed. We find that the sensitivity statistics of these estimators exhibit very similar properties and both estimators are extremely robust to MA(1) disturbances and reasonably robust to AR(1) disturbances except for the cases of severe autocorrelation. The results are useful in light of the rising interest of the SR and PSR techniques in the applied literature.
Year
DOI
Venue
2009
10.1016/j.jmva.2009.03.010
J. Multivariate Analysis
Keywords
Field
DocType
stein-type estimator,psr technique,sensitivity statistic,62j05,ols estimator,positive-part stein-rule,white noise assumption,sensitivity analysis,f statistic,estimators exhibit,non-scalar error covariance structure,white noise,psr estimator,linear regression
Econometrics,M-estimator,Extremum estimator,Shrinkage estimator,White noise,Robustness (computer science),Statistics,Mathematics,Estimator,Autocorrelation,Covariance
Journal
Volume
Issue
ISSN
100
10
Journal of Multivariate Analysis
Citations 
PageRank 
References 
2
0.77
1
Authors
4
Name
Order
Citations
PageRank
Xinyu Zhang162.17
Ti Chen220.77
Alan T. K. Wan3145.28
Guohua Zou4125.72