Expectations of some ratio-type estimators under the gamma distribution

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteur principal: Shih, Jia-Han
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866910932755546112
author Shih, Jia-Han
author_facet Shih, Jia-Han
contents We study the expectations of some ratio-type estimators under the gamma distribution. Expectations of ratio-type estimators are often difficult to compute due to the nature that they are constructed by combining two separate estimators. With the aid of Lukacs' Theorem and the gamma-beta (gamma-Dirichlet) relationship, we provide alternative proofs for the expected values of some common ratio-type estimators, including the sample Gini index, the sample Theil index, and the sample Atkinson index, under the gamma distribution. Our proofs using the distributional properties of the gamma distribution are much simpler than the existing ones. In addition, we also derive the expected value of the sample variance-to-mean ratio under the gamma distribution.
format Preprint
id arxiv_https___arxiv_org_abs_2505_05080
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Expectations of some ratio-type estimators under the gamma distribution
Shih, Jia-Han
Statistics Theory
60E10, 62E10, 62F10
We study the expectations of some ratio-type estimators under the gamma distribution. Expectations of ratio-type estimators are often difficult to compute due to the nature that they are constructed by combining two separate estimators. With the aid of Lukacs' Theorem and the gamma-beta (gamma-Dirichlet) relationship, we provide alternative proofs for the expected values of some common ratio-type estimators, including the sample Gini index, the sample Theil index, and the sample Atkinson index, under the gamma distribution. Our proofs using the distributional properties of the gamma distribution are much simpler than the existing ones. In addition, we also derive the expected value of the sample variance-to-mean ratio under the gamma distribution.
title Expectations of some ratio-type estimators under the gamma distribution
topic Statistics Theory
60E10, 62E10, 62F10
url https://arxiv.org/abs/2505.05080