Explainable AI for delinquency risk monitoring in U.S. auto lease securitizations

  • 12 Views
  • 3 Downloads

Creative Commons License DMCA.com Protection Status
This work is licensed under a Creative Commons Attribution 4.0 International License

Type of the article: Research Article

Abstract
This study evaluates whether explainable machine-learning models can provide reliable and operationally interpretable short-horizon delinquency monitoring in U.S. auto lease securitization panels. Six public SEC ABS-EE trust-family panels were harmonized at the contract-month level. The primary outcome is one-month-ahead incident escalation to 30 or more days past due among contracts below 30 days past due at the feature month. Fully tuned penalized logistic regression (M1), unconstrained gradient boosting (M2), and governance-constrained gradient boosting (M3/X-LEASE) were assessed through chronological development, calibration, locked out-of-time testing, contract-held-out validation, six leave-one-issuer-out experiments, and later temporal evaluation. The locked test comprised 198,301 observations and 768 events. M2 produced the strongest discrimination (AUC-ROC 0.8151; PR-AUC 0.0269), while M3 exceeded the logistic benchmark by PR-AUC but did not outperform M2. At an exact 1% review capacity, each model generated 1,984 alerts; M2 detected 104 events, compared with 61 for M3, so the hypothesized recall advantage of X-LEASE was not supported. Full-sample TreeSHAP analysis showed stable feature rankings across tested issuers, later periods, and contract-level resampling. M3 relied more heavily on credit score and issuer controls and had a more concentrated explanation structure, but this does not establish superior auditability or fairness. The results support human-reviewed early-warning monitoring within the tested securitization panels, not lifetime default prediction, automated adverse decisions, or universal transferability.

Acknowledgments
The authors acknowledge the public availability of SEC EDGAR Form ABS-EE, Exhibit 102 asset-level data. No individuals or institutions outside the author team provided paid analytical, editorial, or funding support for this manuscript.

view full abstract hide full abstract
    • Figure 1. Temporal model-development and evaluation workflow
    • Figure 2. Locked-test precision-recall and calibration curves
    • Figure 3. Held-out-issuer and temporal robustness
    • Figure 4. Full locked-test normalized raw-feature SHAP importance
    • Table 1. Sample composition and selected descriptive statistics
    • Table 2. Model specifications and implemented X-LEASE constraints
    • Table 3. Locked-test discrimination, calibration, and probability performance
    • Table 4. Exact matched top-1% confusion matrices and operational alert burden
    • Table 5. Contract-held-out, LOIO, temporal, and fundamentals-only robustness summary
    • Table 6. Global SHAP importance and explanation-stability summary
    • Table A1. SEC source coverage and grouped analytical panels
    • Table A2. Analytical sample chronology
    • Table B1. Descriptive statistics and missingness summary
    • Table C1. Model specifications and selected settings
    • Table C2. Locked-test discrimination, calibration, and probability performance
    • Table C3. Exact matched top-1% confusion matrices
    • Table D1. Robustness summary
    • Table D2. Explainability and stability diagnostics
    • Table E1. Deterministically selected local cases
    • Table F1. Layered governance interpretation of frozen X-LEASE outputs
    • Conceptualization
      Zhanna Dryha, Oleksandr Levchenko, Liubomyr Kochubei, Kateryna Shcheglova
    • Investigation
      Zhanna Dryha, Oleksandr Levchenko, Larysa Sergiienko, Liubomyr Kochubei, Oleksiy Domashenko, Kateryna Shcheglova
    • Methodology
      Zhanna Dryha, Oleksandr Levchenko, Oleksiy Domashenko, Kateryna Shcheglova
    • Supervision
      Zhanna Dryha, Larysa Sergiienko
    • Validation
      Zhanna Dryha, Larysa Sergiienko, Liubomyr Kochubei, Oleksiy Domashenko
    • Writing – original draft
      Zhanna Dryha, Oleksandr Levchenko
    • Writing – review & editing
      Zhanna Dryha, Oleksandr Levchenko, Larysa Sergiienko, Liubomyr Kochubei, Oleksiy Domashenko, Kateryna Shcheglova
    • Data curation
      Oleksandr Levchenko, Oleksiy Domashenko
    • Formal Analysis
      Oleksandr Levchenko, Oleksiy Domashenko
    • Project administration
      Oleksandr Levchenko
    • Software
      Oleksandr Levchenko
    • Visualization
      Oleksandr Levchenko