Structured Lasso for convex nonparametric least squares: An application to Swedish electricity distribution networks

Fuente: arXiv
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Main Authors: Liao, Zhiqiang, Qu, Zhaonan
Format: Preprint
Published: 2024
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author Liao, Zhiqiang
Qu, Zhaonan
author_facet Liao, Zhiqiang
Qu, Zhaonan
contents We study the problem of variable selection in convex nonparametric least squares (CNLS). Whereas the least absolute shrinkage and selection operator (Lasso) is a popular technique for least squares, its variable selection performance is unknown in CNLS problems. In this work, we investigate the performance of the Lasso estimator and find out it is usually unable to select variables efficiently. Exploiting the unique structure of the subgradients in CNLS, we develop a structured Lasso method by combining $\ell_1$-norm and $\ell_{\infty}$-norm. The relaxed version of the structured Lasso is proposed for achieving model sparsity and predictive performance simultaneously, where we can control the two effects--variable selection and model shrinkage--using separate tuning parameters. A Monte Carlo study is implemented to verify the finite sample performance of the proposed approaches. We also use real data from Swedish electricity distribution networks to illustrate the effects of the proposed variable selection techniques. The results from the simulation and application confirm that the proposed structured Lasso performs favorably, generally leading to sparser and more accurate predictive models, relative to the conventional Lasso methods in the literature.
format Preprint
id arxiv_https___arxiv_org_abs_2409_01911
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Structured Lasso for convex nonparametric least squares: An application to Swedish electricity distribution networks
Liao, Zhiqiang
Qu, Zhaonan
Methodology
Econometrics
We study the problem of variable selection in convex nonparametric least squares (CNLS). Whereas the least absolute shrinkage and selection operator (Lasso) is a popular technique for least squares, its variable selection performance is unknown in CNLS problems. In this work, we investigate the performance of the Lasso estimator and find out it is usually unable to select variables efficiently. Exploiting the unique structure of the subgradients in CNLS, we develop a structured Lasso method by combining $\ell_1$-norm and $\ell_{\infty}$-norm. The relaxed version of the structured Lasso is proposed for achieving model sparsity and predictive performance simultaneously, where we can control the two effects--variable selection and model shrinkage--using separate tuning parameters. A Monte Carlo study is implemented to verify the finite sample performance of the proposed approaches. We also use real data from Swedish electricity distribution networks to illustrate the effects of the proposed variable selection techniques. The results from the simulation and application confirm that the proposed structured Lasso performs favorably, generally leading to sparser and more accurate predictive models, relative to the conventional Lasso methods in the literature.
title Structured Lasso for convex nonparametric least squares: An application to Swedish electricity distribution networks
topic Methodology
Econometrics
url https://arxiv.org/abs/2409.01911