AUC Is Not Enough: A Utility-Aware Comparison of XGBoost and Multi-Task FT Variants for Proxy-Prescriptive Credit Modeling

  • Edinaldo Vicente de Oliveira CESAR School
  • Anderson Tenório Sergio CESAR School

Resumo


Credit-scoring models are often ranked by AUC, yet lending decisions depend on calibrated default probabilities, offer rules, and economic consequences. Using the Home Credit Default Risk benchmark, we compare XGBoost with three multi-task neural baselines: MLP, FT-flat, and source-aware FT-block, under a calibrated proxy-prescriptive workflow. XGBoost achieves the highest AUC (0.7833), with a significant paired-DeLong gap over FT-block (0.7751), but the ranking inverts under proxy utility: FT-block leads in all economic scenarios, about 12% above XGBoost in the base case. FT-flat does not reproduce the inversion, and post-hoc diagnostics localise the effect mainly in the credit/offer channel.
Palavras-chave: credit scoring, tabular deep learning, multi-task learning, probability calibration, utility-aware evaluation

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Publicado
19/10/2026
OLIVEIRA, Edinaldo Vicente de; SERGIO, Anderson Tenório. AUC Is Not Enough: A Utility-Aware Comparison of XGBoost and Multi-Task FT Variants for Proxy-Prescriptive Credit Modeling. In: ENCONTRO NACIONAL DE INTELIGÊNCIA ARTIFICIAL E COMPUTACIONAL (ENIAC), 23. , 2026, Cuiabá/MT. Anais [...]. Porto Alegre: Sociedade Brasileira de Computação, 2026 . p. 2313-2324. ISSN 2763-9061. DOI: https://doi.org/10.5753/eniac.2026.31575.