Volume no :5, Issue no: 2, June (2011)

ESTIMATING A STANDARD DEVIATION WITH U-STATISTICS OF DEGREE MORE THAN TWO: THE NORMAL CASE

Author's: Nitis Mukhopadhyay and Bhargab Chattopadhyay
Pages: [93] - [130]
Received Date: April 20, 2011
Submitted by:

Abstract

We consider unbiased estimation of in a population. Traditional unbiased stimators consist of appropriate multiples of both the sample standard deviation S, that is, and Gini’s mean difference (GMD), that is, Both depend upon U-statistics associated with symmetric kernels of degree two. In this paper, we develop a new approach of constructing higher-order unbiased U-statistics and for based upon symmetric kernels with degree three, four, and four, respectively. From this investigation, we find that the new unbiased estimators for (i) go practically head-to-head with the existing estimators and (ii) beats and (iii) very nearly beats whether n is small or moderately large. In other words, it is our belief that this new approach appears very promising.

Keywords

efficiency, exact variances, Gini’s mean difference, kernel’s degree higher than two, large-sample variances, population standard deviation, sample standard deviation, symmetric kernel, U-statistics, unbiased estimators.