Principal component-guided sparse reduced-rank regression
Kanji Goto, Shintaro Yuki, Kensuke Tanioka, Hiroshi Yadohisa
TL;DR
The paper addresses multivariate regression with correlated responses and high-dimensional, grouped predictors by integrating principal component-guided regularization into reduced-rank regression. The model uses B = CD^T with a rank constraint and introduces group-aware, pcLasso-like penalties to bias coefficients toward high-variance PCs while accounting for within-group correlations, solved via an alternating least squares algorithm. Through extensive simulations and a real gene-expression dataset, the method demonstrates improved predictive accuracy and stability (lower MSE_Y and MSPE) relative to competitors, particularly under small-sample and grouped-variable settings. This approach offers a principled framework for leveraging correlation structures in both responses and explanatory groups to enhance predictive performance in complex multivariate problems.
Abstract
Reduced-rank regression estimates regression coefficients by imposing a low-rank constraint on the matrix of regression coefficients, thereby accounting for correlations among response variables. To further improve predictive accuracy and model interpretability, several regularized reduced-rank regression methods have been proposed. However, these existing methods cannot bias the regression coefficients toward the leading principal component directions while accounting for the correlation structure among explanatory variables. In addition, when the explanatory variables exhibit a group structure, the correlation structure within each group cannot be adequately incorporated.To address these limitations, we propose a new method that introduces pcLasso into the reduced-rank regression framework. The proposed method improves predictive accuracy by accounting for the correlation among response variables while strongly biasing the matrix of regression coefficients toward principal component directions with large variance. Furthermore, even in settings where the explanatory variables possess a group structure, the proposed method is capable of explicitly incorporating this structure into the estimation process. Finally, we illustrate the effectiveness of the proposed method through numerical simulations and real data application.
