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arXiv 2407.00655stat.ME
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马尔可夫切换多方程张量回归

Markov Switching Multiple-equation Tensor Regressions

Roberto Casarin, Radu Craiu, Qing Wang

AI总结:

本文提出马尔可夫切换多方程张量回归模型,利用共同隐马尔可夫过程刻画体制变化,并通过Soft PARAFAC分层先验实现降维与收缩,配合高效MCMC算法,在真实数据上优于Lasso回归。

摘要:

我们提出了一种新的灵活张量模型,用于多方程回归,并考虑了潜在的体制变化。该模型允许动态系数和跨方程变化的多维协变量。我们假设系数由一个共同的隐马尔可夫过程驱动,该过程处理结构突变,以增强模型灵活性并保持简约性。我们引入了一种新的Soft PARAFAC分层先验,以在保留协变量张量结构信息的同时实现降维。所提出的先验包含一种新的多向收缩效应,以解决过度参数化问题。我们建立了有助于超参数选择的理论结果。基于随机扫描Gibbs和回代策略,我们开发了一种高效的MCMC算法,以实现后验采样更好的计算可扩展性。我们从理论上证明了该MCMC算法的有效性,并在不同参数设置下通过数值实验研究了其计算效率。通过两个原创的真实数据分析,展示了该模型框架的有效性。与当前基准Lasso回归相比,所提出的模型表现出优越的性能。

英文摘要:

We propose a new flexible tensor model for multiple-equation regression that accounts for latent regime changes. The model allows for dynamic coefficients and multi-dimensional covariates that vary across equations. We assume the coefficients are driven by a common hidden Markov process that addresses structural breaks to enhance the model flexibility and preserve parsimony. We introduce a new Soft PARAFAC hierarchical prior to achieve dimensionality reduction while preserving the structural information of the covariate tensor. The proposed prior includes a new multi-way shrinking effect to address over-parametrization issues. We developed theoretical results to help hyperparameter choice. An efficient MCMC algorithm based on random scan Gibbs and back-fitting strategy is developed to achieve better computational scalability of the posterior sampling. The validity of the MCMC algorithm is demonstrated theoretically, and its computational efficiency is studied using numerical experiments in different parameter settings. The effectiveness of the model framework is illustrated using two original real data analyses. The proposed model exhibits superior performance when compared to the current benchmark, Lasso regression.

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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