Robust estimation for high-dimensional time series with heavy tails

Fuente: arXiv
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Auteurs principaux: Wang, Yu, Li, Guodong, Xiao, Zhijie, Xu, Lihu, Zhang, Wenyang
Format: Preprint
Publié: 2024
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author Wang, Yu
Li, Guodong
Xiao, Zhijie
Xu, Lihu
Zhang, Wenyang
author_facet Wang, Yu
Li, Guodong
Xiao, Zhijie
Xu, Lihu
Zhang, Wenyang
contents We study in this paper the problem of least absolute deviation (LAD) regression for high-dimensional heavy-tailed time series which have finite $α$-th moment with $α\in (1,2]$. To handle the heavy-tailed dependent data, we propose a Catoni type truncated minimization problem framework and obtain an $\mathcal{O}\big( \big( (d_1+d_2) (d_1\land d_2) \log^2 n / n \big)^{(α- 1)/α} \big)$ order excess risk, where $d_1$ and $d_2$ are the dimensionality and $n$ is the number of samples. We apply our result to study the LAD regression on high-dimensional heavy-tailed vector autoregressive (VAR) process. Simulations for the VAR($p$) model show that our new estimator with truncation are essential because the risk of the classical LAD has a tendency to blow up. We further apply our estimation to the real data and find that ours fits the data better than the classical LAD.
format Preprint
id arxiv_https___arxiv_org_abs_2411_05217
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Robust estimation for high-dimensional time series with heavy tails
Wang, Yu
Li, Guodong
Xiao, Zhijie
Xu, Lihu
Zhang, Wenyang
Statistics Theory
We study in this paper the problem of least absolute deviation (LAD) regression for high-dimensional heavy-tailed time series which have finite $α$-th moment with $α\in (1,2]$. To handle the heavy-tailed dependent data, we propose a Catoni type truncated minimization problem framework and obtain an $\mathcal{O}\big( \big( (d_1+d_2) (d_1\land d_2) \log^2 n / n \big)^{(α- 1)/α} \big)$ order excess risk, where $d_1$ and $d_2$ are the dimensionality and $n$ is the number of samples. We apply our result to study the LAD regression on high-dimensional heavy-tailed vector autoregressive (VAR) process. Simulations for the VAR($p$) model show that our new estimator with truncation are essential because the risk of the classical LAD has a tendency to blow up. We further apply our estimation to the real data and find that ours fits the data better than the classical LAD.
title Robust estimation for high-dimensional time series with heavy tails
topic Statistics Theory
url https://arxiv.org/abs/2411.05217