From Binary to Three-Way Decisions in Credit Scoring: An Enhanced Cost-Sensitive Boosting Model with Incremental Learning
摘要
To improve the identification of medium-risk samples in credit risk assessment, this study integrates three-way decision with incremental learning and proposes an enhanced cost-sensitive Boosting model, extending traditional binary credit approval to ternary decision-making. To overcome the limitations of existing three-way decision (3WD) methods, which rely on static datasets, offline threshold optimization, and accuracy-driven threshold learning, the proposed model dynamically updates boundary thresholds as credit data arrive sequentially. It also constructs a dynamic cost matrix incorporating both misclassification and evaluation costs, enabling threshold learning to be guided by expected economic loss. In addition, incremental learning is embedded as an endogenous mechanism for boundary-sample re-evaluation and dynamic threshold optimization. By continuously integrating newly arrived, misclassified, and boundary-region samples, the model more effectively identifies uncertain cases, adapts to evolving data distributions, and strengthens decision support in dynamic credit environments. Interpretability analysis further reveals the key drivers of model decisions.