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arXiv 2302.02672stat.MLcs.LG
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潜变量与结构方程模型的可识别性:从线性到非线性

Identifiability of latent-variable and structural-equation models: from linear to nonlinear

University of Helsinki(赫尔辛基大学);UCL(伦敦大学学院)

Aapo Hyvärinen, Ilyes Khemakhem, Ricardo Monti

AI总结:

本文综述了潜变量与结构方程模型的可识别性理论,梳理了线性场景下非高斯性解决可识别性问题的思路,以及非线性场景下结合时间序列或辅助变量实现可识别性的最新进展。

摘要:

多元统计学中的一个经典问题是线性高斯模型通常不具备可识别性,即部分参数无法被唯一估计。在因子(成分)分析中,因子的正交旋转是不可识别的;而在线性回归中,效应的方向无法被确定。对于这类线性模型,已有研究证明(潜)变量的非高斯性可以提供可识别性。在因子分析场景下,这催生了独立成分分析(independent component analysis);而在效应方向识别的场景下,结构方程建模(structural equation modelling)的非高斯版本解决了该问题。近期,我们证明了这类模型甚至其通用非参数非线性版本都可以被估计。在这种情况下,非高斯性不足以保证可识别性,但假设我们拥有时间序列数据,或者分布由某些观测到的辅助变量进行了恰当调制,模型就是可识别的。本文综述了线性与非线性情形下的可识别性理论,同时涵盖因子分析模型与结构方程模型两类模型。

英文摘要:

An old problem in multivariate statistics is that linear Gaussian models are often unidentifiable, i.e. some parameters cannot be uniquely estimated. In factor (component) analysis, an orthogonal rotation of the factors is unidentifiable, while in linear regression, the direction of effect cannot be identified. For such linear models, non-Gaussianity of the (latent) variables has been shown to provide identifiability. In the case of factor analysis, this leads to independent component analysis, while in the case of the direction of effect, non-Gaussian versions of structural equation modelling solve the problem. More recently, we have shown how even general nonparametric nonlinear versions of such models can be estimated. Non-Gaussianity is not enough in this case, but assuming we have time series, or that the distributions are suitably modulated by some observed auxiliary variables, the models are identifiable. This paper reviews the identifiability theory for the linear and nonlinear cases, considering both factor analytic models and structural equation models.

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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