On the Structural Dimension of Sliced Inverse Regression

Fuente: arXiv
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Autores principales: Huang, Dongming, Tian, Songtao, Lin, Qian
Formato: Preprint
Publicado: 2023
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author Huang, Dongming
Tian, Songtao
Lin, Qian
author_facet Huang, Dongming
Tian, Songtao
Lin, Qian
contents In this work, we address the longstanding puzzle that Sliced Inverse Regression (SIR) often performs poorly for sufficient dimension reduction when the structural dimension $d$ (the dimension of the central space) exceeds 4. We first show that in the multiple index model $Y=f( \mathbf{P} \boldsymbol{X})+ε$ where $\boldsymbol{X}$ is a $p$-standard normal vector, $ε$ is an independent noise, and $\mathbf{P}$ is a projection operator from $\mathbb R^{p}$ to $\mathbb R^{d}$, if the link function $f$ follows the law of a Gaussian process, then with high probability, the $d$-th eigenvalue $λ_{d}$ of $\mathrm{Cov}\left[\mathbb{E}(\boldsymbol{X}\mid Y)\right]$ satisfies $λ_{d}\leq C e^{-θd}$ for some positive constants $C$ and $θ$. We then focus on the low signal regime where $λ_{d}$ can be arbitrarily small and not larger than $d^{-8.1}$, and prove that the minimax risk of estimating the central space is lower bounded by $\frac{dp}{nλ_{d}}$. Combining these two results, we provide a convincing explanation for the poor performance of SIR when $d$ is large, a phenomenon that has perplexed researchers for nearly three decades. The technical tools developed here may be of independent interest for studying other sufficient dimension reduction methods.
format Preprint
id arxiv_https___arxiv_org_abs_2305_04340
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle On the Structural Dimension of Sliced Inverse Regression
Huang, Dongming
Tian, Songtao
Lin, Qian
Statistics Theory
62J02 (Primary) 62H12, 62C20 (Secondary)
In this work, we address the longstanding puzzle that Sliced Inverse Regression (SIR) often performs poorly for sufficient dimension reduction when the structural dimension $d$ (the dimension of the central space) exceeds 4. We first show that in the multiple index model $Y=f( \mathbf{P} \boldsymbol{X})+ε$ where $\boldsymbol{X}$ is a $p$-standard normal vector, $ε$ is an independent noise, and $\mathbf{P}$ is a projection operator from $\mathbb R^{p}$ to $\mathbb R^{d}$, if the link function $f$ follows the law of a Gaussian process, then with high probability, the $d$-th eigenvalue $λ_{d}$ of $\mathrm{Cov}\left[\mathbb{E}(\boldsymbol{X}\mid Y)\right]$ satisfies $λ_{d}\leq C e^{-θd}$ for some positive constants $C$ and $θ$. We then focus on the low signal regime where $λ_{d}$ can be arbitrarily small and not larger than $d^{-8.1}$, and prove that the minimax risk of estimating the central space is lower bounded by $\frac{dp}{nλ_{d}}$. Combining these two results, we provide a convincing explanation for the poor performance of SIR when $d$ is large, a phenomenon that has perplexed researchers for nearly three decades. The technical tools developed here may be of independent interest for studying other sufficient dimension reduction methods.
title On the Structural Dimension of Sliced Inverse Regression
topic Statistics Theory
62J02 (Primary) 62H12, 62C20 (Secondary)
url https://arxiv.org/abs/2305.04340