New two parameter hybrid estimator for zero inflated negative binomial regression models

The zero-inflated negative binomial regression (ZINBR) model is used for modeling count data that exhibit both overdispersion and zero-inflated counts. However, a persistent challenge in the efficient estimation of parameters within ZINBR models is the issue of multicollinearity, where high correlations between predictor variables can compromise the stability and reliability of the maximum likelihood estimator (MLE). We propose a new two-parameter hybrid estimator, designed for the ZINBR model, to address this problem. This estimator aims to mitigate the effects of multicollinearity by incorporating a combination of existing biased estimators. To test the effectiveness of the proposed estimator, we conduct a comprehensive theoretical comparison with conventional biased estimators, including the Ridge and Liu, the Kibria-Lukman, and the modified Ridge estimators. An extended Monte Carlo simulation study complements the theoretical results, evaluating the estimator's performance under various multicollinearity conditions. The simulation results, evaluated by metrics such as mean squared error (MSE) and mean absolute error (MAE), show that the proposed hybrid estimator consistently outperforms conventional methods, especially in high multicollinearity. Furthermore, we apply it to two real-world datasets. The experimental application demonstrates the superior performance of the estimator in producing stable and accurate parameter estimates. The simulation study and experimental application results strongly suggest that the new two-parameter hybrid estimator offers significant progress in parameter estimation in ZINBR models, especially in complex scenarios due to multicollinearity.