论文标题

一般无模型的加权信封估计

General model-free weighted envelope estimation

论文作者

Eck, Daniel J.

论文摘要

包络方法可简洁地作为一类程序,用于提高多变量分析的效率,而不会改变传统目标\ citep [第1页的第1句] {cook2018introduction}。这种描述是正确的,即通过模型选择波动率在未知程度的模型选择波动率来减轻额外的警告。当前的包络方法文献的大部分并不能解释这一增加的差异,而这种差异是由模型选择中的不确定性引起的。最近在两个方面进行了解释模型选择波动率的大步:1)在多元回归的背景下,加权信封估计量的开发直接考虑了这种可变性; 2)开发模型选择标准,该标准有助于对更通用设置的正确包络模型进行一致的估计。在本文中,我们统一了这两个方向,并提供了加权的包络估计器,这些估计量直接说明与模型选择相关的可变性,并且适用于矢量值参数的一般多元估计设置。我们的加权估计技术为从业者提供了有限样本的稳健差异。为我们的估计器提供了理论上的理由,并建立了非参数引导程序的有效性,以估算其渐近方差。仿真研究和实际数据分析支持我们的主张,并在存在模型选择变异性时证明了我们加权信封估计器的优势。

Envelope methodology is succinctly pitched as a class of procedures for increasing efficiency in multivariate analyses without altering traditional objectives \citep[first sentence of page 1]{cook2018introduction}. This description is true with the additional caveat that the efficiency gains obtained by envelope methodology are mitigated by model selection volatility to an unknown degree. The bulk of the current envelope methodology literature does not account for this added variance that arises from the uncertainty in model selection. Recent strides to account for model selection volatility have been made on two fronts: 1) development of a weighted envelope estimator, in the context of multivariate regression, to account for this variability directly; 2) development of a model selection criterion that facilitates consistent estimation of the correct envelope model for more general settings. In this paper, we unify these two directions and provide weighted envelope estimators that directly account for the variability associated with model selection and are appropriate for general multivariate estimation settings for vector valued parameters. Our weighted estimation technique provides practitioners with robust and useful variance reduction in finite samples. Theoretical justification is given for our estimators and validity of a nonparametric bootstrap procedure for estimating their asymptotic variance are established. Simulation studies and a real data analysis support our claims and demonstrate the advantage of our weighted envelope estimator when model selection variability is present.

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