Modified Two-Parameter Ridge Estimators for Enhanced Regression Performance in the Presence of Multicollinearity: Simulations and Medical Data Applications

Predictive regression models often face a common challenge known as multicollinearity. This phenomenon can distort the results, causing models to overfit and produce unreliable coefficient estimates. Ridge regression is a widely used approach that incorporates a regularization term to stabilize para...

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Main Authors: Muteb Faraj Alharthi, Nadeem Akhtar
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Axioms
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Online Access:https://www.mdpi.com/2075-1680/14/7/527
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author Muteb Faraj Alharthi
Nadeem Akhtar
author_facet Muteb Faraj Alharthi
Nadeem Akhtar
author_sort Muteb Faraj Alharthi
collection DOAJ
description Predictive regression models often face a common challenge known as multicollinearity. This phenomenon can distort the results, causing models to overfit and produce unreliable coefficient estimates. Ridge regression is a widely used approach that incorporates a regularization term to stabilize parameter estimates and improve the prediction accuracy. In this study, we introduce four newly modified ridge estimators, referred to as RIRE1, RIRE2, RIRE3, and RIRE4, that are aimed at tackling severe multicollinearity more effectively than ordinary least squares (OLS) and other existing estimators under both normal and non-normal error distributions. The ridge estimators are biased, so their efficiency cannot be judged by variance alone; instead, we use the mean squared error (MSE) to compare their performance. Each new estimator depends on two shrinkage parameters, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>k</mi></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>d</mi></mrow></semantics></math></inline-formula>, making the theoretical analysis complex. To address this, we employ Monte Carlo simulations to rigorously evaluate and compare these new estimators with OLS and other existing ridge estimators. Our simulations show that the proposed estimators consistently minimize the MSE better than OLS and other ridge estimators, particularly in datasets with strong multicollinearity and large error variances. We further validate their practical value through applications using two real-world datasets, demonstrating both their robustness and theoretical alignment.
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spelling doaj-art-3fbe178863814c899d2a355a231673662025-08-20T02:45:43ZengMDPI AGAxioms2075-16802025-07-0114752710.3390/axioms14070527Modified Two-Parameter Ridge Estimators for Enhanced Regression Performance in the Presence of Multicollinearity: Simulations and Medical Data ApplicationsMuteb Faraj Alharthi0Nadeem Akhtar1Department of Mathematics and Statistics, College of Science, Taif University, Taif 21944, Saudi ArabiaGovernment Degree College Achini Payan, Higher Education, Archives and Libraries Department, Peshawar 25000, Khyber Pakhtunkhwa, PakistanPredictive regression models often face a common challenge known as multicollinearity. This phenomenon can distort the results, causing models to overfit and produce unreliable coefficient estimates. Ridge regression is a widely used approach that incorporates a regularization term to stabilize parameter estimates and improve the prediction accuracy. In this study, we introduce four newly modified ridge estimators, referred to as RIRE1, RIRE2, RIRE3, and RIRE4, that are aimed at tackling severe multicollinearity more effectively than ordinary least squares (OLS) and other existing estimators under both normal and non-normal error distributions. The ridge estimators are biased, so their efficiency cannot be judged by variance alone; instead, we use the mean squared error (MSE) to compare their performance. Each new estimator depends on two shrinkage parameters, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>k</mi></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>d</mi></mrow></semantics></math></inline-formula>, making the theoretical analysis complex. To address this, we employ Monte Carlo simulations to rigorously evaluate and compare these new estimators with OLS and other existing ridge estimators. Our simulations show that the proposed estimators consistently minimize the MSE better than OLS and other ridge estimators, particularly in datasets with strong multicollinearity and large error variances. We further validate their practical value through applications using two real-world datasets, demonstrating both their robustness and theoretical alignment.https://www.mdpi.com/2075-1680/14/7/527regression modelsmulticollinearityridge estimatorsmean squared error (MSE)Monte Carlo simulationscomputational analysis
spellingShingle Muteb Faraj Alharthi
Nadeem Akhtar
Modified Two-Parameter Ridge Estimators for Enhanced Regression Performance in the Presence of Multicollinearity: Simulations and Medical Data Applications
Axioms
regression models
multicollinearity
ridge estimators
mean squared error (MSE)
Monte Carlo simulations
computational analysis
title Modified Two-Parameter Ridge Estimators for Enhanced Regression Performance in the Presence of Multicollinearity: Simulations and Medical Data Applications
title_full Modified Two-Parameter Ridge Estimators for Enhanced Regression Performance in the Presence of Multicollinearity: Simulations and Medical Data Applications
title_fullStr Modified Two-Parameter Ridge Estimators for Enhanced Regression Performance in the Presence of Multicollinearity: Simulations and Medical Data Applications
title_full_unstemmed Modified Two-Parameter Ridge Estimators for Enhanced Regression Performance in the Presence of Multicollinearity: Simulations and Medical Data Applications
title_short Modified Two-Parameter Ridge Estimators for Enhanced Regression Performance in the Presence of Multicollinearity: Simulations and Medical Data Applications
title_sort modified two parameter ridge estimators for enhanced regression performance in the presence of multicollinearity simulations and medical data applications
topic regression models
multicollinearity
ridge estimators
mean squared error (MSE)
Monte Carlo simulations
computational analysis
url https://www.mdpi.com/2075-1680/14/7/527
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