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Weak signals in high‐dimensional regression: Detection, estimation and prediction
Author(s) -
Li Yanming,
Hong Hyokyoung G.,
Ahmed S. Ejaz,
Li Yi
Publication year - 2018
Publication title -
applied stochastic models in business and industry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.413
H-Index - 40
eISSN - 1526-4025
pISSN - 1524-1904
DOI - 10.1002/asmb.2340
Subject(s) - lasso (programming language) , estimator , feature selection , covariance , instrumental variable , selection (genetic algorithm) , regression , econometrics , shrinkage estimator , computer science , statistics , mathematics , regularization (linguistics) , artificial intelligence , bias of an estimator , minimum variance unbiased estimator , world wide web
Regularization methods, including Lasso, group Lasso, and SCAD, typically focus on selecting variables with strong effects while ignoring weak signals. This may result in biased prediction, especially when weak signals outnumber strong signals. This paper aims to incorporate weak signals in variable selection, estimation, and prediction. We propose a two‐stage procedure, consisting of variable selection and postselection estimation. The variable selection stage involves a covariance‐insured screening for detecting weak signals, whereas the postselection estimation stage involves a shrinkage estimator for jointly estimating strong and weak signals selected from the first stage. We term the proposed method as the covariance‐insured screening‐based postselection shrinkage estimator. We establish asymptotic properties for the proposed method and show, via simulations, that incorporating weak signals can improve estimation and prediction performance. We apply the proposed method to predict the annual gross domestic product rates based on various socioeconomic indicators for 82 countries.