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Main Author: Zhang, Qingyang
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2403.17882
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author Zhang, Qingyang
author_facet Zhang, Qingyang
contents Pearson's Chi-squared test, though widely used for detecting association between categorical variables, exhibits low statistical power in large sparse contingency tables. To address this limitation, two novel permutation tests have been recently developed: the distance covariance permutation test and the U-statistic permutation test. Both leverage the distance covariance functional but employ different estimators. In this work, we explore key statistical properties of the distance covariance for categorical variables. Firstly, we show that unlike Chi-squared, the distance covariance functional is B-robust for any number of categories (fixed or diverging). Second, we establish the strong consistency of distance covariance screening under mild conditions, and simulations confirm its advantage over Chi-squared screening, especially for large sparse tables. Finally, we derive an approximate null distribution for a bias-corrected distance correlation estimate, demonstrating its effectiveness through simulations.
format Preprint
id arxiv_https___arxiv_org_abs_2403_17882
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On the properties of distance covariance for categorical data: Robustness, sure screening, and approximate null distributions
Zhang, Qingyang
Methodology
Pearson's Chi-squared test, though widely used for detecting association between categorical variables, exhibits low statistical power in large sparse contingency tables. To address this limitation, two novel permutation tests have been recently developed: the distance covariance permutation test and the U-statistic permutation test. Both leverage the distance covariance functional but employ different estimators. In this work, we explore key statistical properties of the distance covariance for categorical variables. Firstly, we show that unlike Chi-squared, the distance covariance functional is B-robust for any number of categories (fixed or diverging). Second, we establish the strong consistency of distance covariance screening under mild conditions, and simulations confirm its advantage over Chi-squared screening, especially for large sparse tables. Finally, we derive an approximate null distribution for a bias-corrected distance correlation estimate, demonstrating its effectiveness through simulations.
title On the properties of distance covariance for categorical data: Robustness, sure screening, and approximate null distributions
topic Methodology
url https://arxiv.org/abs/2403.17882