Causal Discovery of Linear Non-Gaussian Causal Models with Unobserved Confounding

Fuente: arXiv
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Autores principales: Schkoda, Daniela, Robeva, Elina, Drton, Mathias
Formato: Preprint
Publicado: 2024
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author Schkoda, Daniela
Robeva, Elina
Drton, Mathias
author_facet Schkoda, Daniela
Robeva, Elina
Drton, Mathias
contents We consider linear non-Gaussian structural equation models that involve latent confounding. In this setting, the causal structure is identifiable, but, in general, it is not possible to identify the specific causal effects. Instead, a finite number of different causal effects result in the same observational distribution. Most existing algorithms for identifying these causal effects use overcomplete independent component analysis (ICA), which often suffers from convergence to local optima. Furthermore, the number of latent variables must be known a priori. To address these issues, we propose an algorithm that operates recursively rather than using overcomplete ICA. The algorithm first infers a source, estimates the effect of the source and its latent parents on their descendants, and then eliminates their influence from the data. For both source identification and effect size estimation, we use rank conditions on matrices formed from higher-order cumulants. We prove asymptotic correctness under the mild assumption that locally, the number of latent variables never exceeds the number of observed variables. Simulation studies demonstrate that our method achieves comparable performance to overcomplete ICA even though it does not know the number of latents in advance.
format Preprint
id arxiv_https___arxiv_org_abs_2408_04907
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Causal Discovery of Linear Non-Gaussian Causal Models with Unobserved Confounding
Schkoda, Daniela
Robeva, Elina
Drton, Mathias
Machine Learning
Methodology
We consider linear non-Gaussian structural equation models that involve latent confounding. In this setting, the causal structure is identifiable, but, in general, it is not possible to identify the specific causal effects. Instead, a finite number of different causal effects result in the same observational distribution. Most existing algorithms for identifying these causal effects use overcomplete independent component analysis (ICA), which often suffers from convergence to local optima. Furthermore, the number of latent variables must be known a priori. To address these issues, we propose an algorithm that operates recursively rather than using overcomplete ICA. The algorithm first infers a source, estimates the effect of the source and its latent parents on their descendants, and then eliminates their influence from the data. For both source identification and effect size estimation, we use rank conditions on matrices formed from higher-order cumulants. We prove asymptotic correctness under the mild assumption that locally, the number of latent variables never exceeds the number of observed variables. Simulation studies demonstrate that our method achieves comparable performance to overcomplete ICA even though it does not know the number of latents in advance.
title Causal Discovery of Linear Non-Gaussian Causal Models with Unobserved Confounding
topic Machine Learning
Methodology
url https://arxiv.org/abs/2408.04907