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arXiv 2309.12902stat.MEecon.TH
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降秩包络向量自回归模型

Reduced-rank Envelope Vector Autoregressive Models

S. Yaser Samadi, Wiranthe B. Herath

AI总结:

本文提出降秩包络 VAR(REVAR)模型,融合降秩 VAR 与包络 VAR 的优势,以同时解决 VAR 模型过度参数化、信息提取效率低和秩亏问题,并通过理论、模拟和实际数据验证其效率和准确性提升。

摘要:

标准向量自回归(VAR)模型存在过度参数化问题,这对于高维时间序列数据而言是一个严重问题,因为它限制了可以纳入模型的变量数量和滞后阶数。若干统计方法,例如多元(多重)时间序列的降秩模型(Velu 等,1986;Reinsel 和 Velu,1998;Reinsel 等,2022)以及包络 VAR 模型(Wang 和 Ding,2018),为 VAR 模型参数空间的降维提供了解决方案。然而,这些方法在从复杂数据中提取相关信息方面可能效率不高,因为它们未能区分相关信息与无关信息,或者在处理秩亏问题方面效率不足。我们将包络模型的思想融入降秩 VAR 模型,以同时应对这些挑战,并提出经典 VAR 模型的一种新的简约版本,称为降秩包络 VAR(REVAR)模型。我们提出的 REVAR 模型结合了降秩 VAR 和包络 VAR 模型的优势,并在效率和准确性方面带来显著提升。在不同误差假设下建立了所提估计量的渐近性质。通过模拟研究和实际数据分析对所提方法进行了评估和说明。

英文摘要:

The standard vector autoregressive (VAR) models suffer from overparameterization which is a serious issue for high-dimensional time series data as it restricts the number of variables and lags that can be incorporated into the model. Several statistical methods, such as the reduced-rank model for multivariate (multiple) time series (Velu et al., 1986; Reinsel and Velu, 1998; Reinsel et al., 2022) and the Envelope VAR model (Wang and Ding, 2018), provide solutions for achieving dimension reduction of the parameter space of the VAR model. However, these methods can be inefficient in extracting relevant information from complex data, as they fail to distinguish between relevant and irrelevant information, or they are inefficient in addressing the rank deficiency problem. We put together the idea of envelope models into the reduced-rank VAR model to simultaneously tackle these challenges, and propose a new parsimonious version of the classical VAR model called the reduced-rank envelope VAR (REVAR) model. Our proposed REVAR model incorporates the strengths of both reduced-rank VAR and envelope VAR models and leads to significant gains in efficiency and accuracy. The asymptotic properties of the proposed estimators are established under different error assumptions. Simulation studies and real data analysis are conducted to evaluate and illustrate the proposed method.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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