Generalized Ridge Refitting for the Lasso and Prediction Improvement Bounds
Abstract
We study a class of Lasso based estimators obtained by applying a quadratic correction on the Lasso equicorrelation set. The penalty matrix determines both the magnitude and geometry of the correction and contains, among other cases, the isotropic Lasso--Ridge correction, least squares refitting, Gram proportional interpolation between the Lasso and least squares, and coordinate specific penalties. We first derive a closed form representation and isolate the positive gain component of the resulting prediction improvement. We then control the remaining stochastic linear term in expectation by localizing the random signed equicorrelation model around a deterministic reference support. This yields a finite sample expectation bound that explicitly accounts for the randomness induced by Lasso model selection. The resulting decomposition provides a unified framework for understanding when Lasso based quadratic corrections can improve prediction.
Related
- A Generalized Ridge Regression and Convolutional LASSO
- Robust Error Bounds for Vector-Valued Kernel Ridge Regression
- A Movie Rating Prediction Method Based on Structured Prior Integration and Target-Aware User Interest with Ridge-Based Calibration
- Hierarchical Melnikov Realization: Logarithmic Factor Improvement to Hilbert Number Lower Bounds
- Constant-List Insertion--Deletion Codes:New Bounds and an Improvement of Levenshtein's Lower Bound
BibTeX
@misc{liu2026generalized,
title = {{Generalized Ridge Refitting for the Lasso and Prediction Improvement Bounds}},
author = {Guo Liu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.10933},
eprint = {2609.10933},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.10933},
}
RIS
TY - UNPB
TI - Generalized Ridge Refitting for the Lasso and Prediction Improvement Bounds
AU - Guo Liu
PY - 2026
DA - 2026/09/10
PB - arXiv
DO - 10.48550/arxiv.2609.10933
UR - https://arxiv.org/abs/2609.10933
AB - We study a class of Lasso based estimators obtained by applying a quadratic correction on the Lasso equicorrelation set. The penalty matrix determines both the magnitude and geometry of the correction and contains, among other cases, the isotropic Lasso--Ridge correction, least squares refitting, Gram proportional interpolation between the Lasso and least squares, and coordinate specific penalties. We first derive a closed form representation and isolate the positive gain component of the resulting prediction improvement. We then control the remaining stochastic linear term in expectation by localizing the random signed equicorrelation model around a deterministic reference support. This yields a finite sample expectation bound that explicitly accounts for the randomness induced by Lasso model selection. The resulting decomposition provides a unified framework for understanding when Lasso based quadratic corrections can improve prediction.
ER -