Model Selection in High-Dimensional Linear Regression using Boosting with Multiple Testing

TL;DR

This paper introduces Boosting with Multiple Testing (BMT), a new method for high-dimensional linear regression that combines variable selection with multiple testing to improve model accuracy and interpretability.

Contribution

The paper proposes BMT, a novel approach that integrates boosting and multiple testing, providing oracle properties and improved model selection in high-dimensional settings.

Findings

BMT achieves oracle properties and consistent model selection.

BMT outperforms Lasso and OCMT in accuracy and RMSE.

Empirical results show BMT yields sparse, interpretable models with good out-of-sample performance.

Abstract

High-dimensional regression specification and analysis is a complex and active area of research in statistics, machine learning, and econometrics. This paper proposes a new approach, Boosting with Multiple Testing (BMT), which combines forward stepwise variable selection with the multiple testing framework of Chudik et al (2018). At each stage, the model is updated by adding only the most significant regressor conditional on those already included, while a family-wise multiple testing filter is applied to the remaining candidates. In this way, the method retains the strong screening properties of Chudik et al (2018) while operating in a less greedy manner with respect to proxy and noise variables. Using sharp probability inequalities for heterogeneous strongly mixing processes from Dendramis et al (2022), we show that BMT enjoys oracle type properties relative to an approximating model that includes all true signals and excludes pure noise variables: this model is selected with probability tending to one, and the resulting estimator achieves standard parametric rates for prediction error and coefficient estimation. Additional results establish conditions under which BMT recovers the exact true model and avoids selection of proxy signals. Monte Carlo experiments indicate that BMT performs very well relative to OCMT and Lasso type procedures, delivering higher model selection accuracy and smaller RMSE for the estimated coefficients, especially under strong multicollinearity of the regressors. Two empirical illustrations based on a large set of macro-financial indicators as covariates, show that BMT yields sparse, interpretable specifications with favourable out-of-sample performance.