eprintid: 21410 rev_number: 12 eprint_status: archive userid: 2326 dir: disk0/00/02/14/10 datestamp: 2016-06-27 15:06:22 lastmod: 2016-07-22 11:15:14 status_changed: 2016-06-27 15:06:22 type: workingPaper metadata_visibility: show creators_name: Beran, Rudolf title: Stein Estimation in High Dimensions and the Bootstrap subjects: ddc-510 divisions: i-110400 keywords: Admissible; minimax; high dimension; orthogonal group; equivariant; directional statistics abstract: The Stein estimator and the better positive-part Stein estimatorboth dominate the sample mean, under quadratic loss, in the standardmultivariate model of dimension q. Standard large sample theory does notexplain this phenomenon well. Plausible bootstrap estimators for the riskof the Stein estimator do not converge correctly at the shrinkage point assample size n increases. By analyzing a submodel exactly, with the helpof results from directional statistics, and then letting dimension q go toinfinity, we find:a) In high dimensions, the Stein and positive-part Stein estimators areapproximately admissible and approximately minimax on large compact ballsabout the shrinkage point. The sample mean is neither.b) A new estimator, asymptotically equivalent as dimension q tends toinfinity, appears to dominate the positive-part Stein estimator slightlyfor finite q.c) Resampling from a fitted standard multivariate normal distribution inwhich the length of the fitted mean vector estimates the length of thetrue mean vector well is the key to consistent bootstrap risk estimationfor Stein estimators. date: 1993-08 id_scheme: DOI id_number: 10.11588/heidok.00021410 schriftenreihe_cluster_id: sr-10a schriftenreihe_order: 01 ppn_swb: 1657873412 own_urn: urn:nbn:de:bsz:16-heidok-214106 language: eng bibsort: BERANRUDOLSTEINESTIM199308 full_text_status: public place_of_pub: Heidelberg pages: 19 edition: revised August 1993 citation: Beran, Rudolf (1993) Stein Estimation in High Dimensions and the Bootstrap. [Working paper] document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/21410/1/beitrag.01.pdf