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Bibliographic Details
Main Authors: Maruyama, Yuzo, Takemura, Akimichi
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2509.17504
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author Maruyama, Yuzo
Takemura, Akimichi
author_facet Maruyama, Yuzo
Takemura, Akimichi
contents This paper presents a novel approach to constructing estimators that dominate the classical James-Stein estimator under the quadratic loss for multivariate normal means. Building on Stein's risk representation, we introduce a new sufficient condition involving a monotonicity property of a transformed shrinkage function. We derive a general class of shrinkage estimators that satisfy minimaxity and dominance over the James-Stein estimator, including cases with polynomial or logarithmic convergence to the optimal shrinkage factor. We also provide conditions for uniform dominance across dimensions and for improved asymptotic risk performance. We present several examples and numerical validations to illustrate the theoretical results.
format Preprint
id arxiv_https___arxiv_org_abs_2509_17504
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A new perspective on dominating the James-Stein estimator
Maruyama, Yuzo
Takemura, Akimichi
Statistics Theory
This paper presents a novel approach to constructing estimators that dominate the classical James-Stein estimator under the quadratic loss for multivariate normal means. Building on Stein's risk representation, we introduce a new sufficient condition involving a monotonicity property of a transformed shrinkage function. We derive a general class of shrinkage estimators that satisfy minimaxity and dominance over the James-Stein estimator, including cases with polynomial or logarithmic convergence to the optimal shrinkage factor. We also provide conditions for uniform dominance across dimensions and for improved asymptotic risk performance. We present several examples and numerical validations to illustrate the theoretical results.
title A new perspective on dominating the James-Stein estimator
topic Statistics Theory
url https://arxiv.org/abs/2509.17504