International Journal of Education, Vocational and Social Science
Vol. 5 No. 04 (2026): International Journal of Education, Vocational and Social Science( IJVESS)

Beyond Accuracy: Leakage-Audited Machine Learning for Explainable Microcredit Risk Screening at Bank Mandiri

Puja Malika (Information Systems Study Program, Universitas Bina Darma, Palembang, Indonesia)
Ari Muzakir (Information Systems Study Program, Universitas Bina Darma, Palembang, Indonesia)
Evi Yulianingsih (Information Systems Study Program, Universitas Bina Darma, Palembang, Indonesia)
Maria Ulfa (Information Systems Study Program, Universitas Bina Darma, Palembang, Indonesia)
Nia Oktaviani (Information Systems Study Program, Universitas Bina Darma, Palembang, Indonesia)



Article Info

Publish Date
11 Sep 2026

Abstract

Accuracy can misrank models when at-risk borrowers are rare and missed risk is costlier than unnecessary review. This study evaluates a leakage-audited, explainable machine-learning framework for microcredit risk screening at Bank Mandiri and addresses prior work that rarely links temporal feature availability, class imbalance, and asymmetric error costs. A quantitative cross-sectional experiment used 1,718 anonymized active-facility records from four Palembang microbusiness units. An audit reduced 29 candidate fields to 13 operational predictors. Logistic Regression, Decision Tree, and Random Forest were evaluated through a stratified 80:20 split and training-only fivefold cross-validation. A tuned Decision Tree achieved the highest test accuracy (96.22%; 331/344) but detected 15 of 24 at-risk facilities. Random Forest at a training-selected 0.46 threshold achieved 95.35% accuracy and detected 18 of 24. The accuracy difference was not significant (exact McNemar p = .607). Cost analysis showed that thresholded Random Forest becomes preferable when a false negative costs more than twice a false positive. Account liquidity explained 88.72% of Decision Tree impurity reduction. The study contributes a transparent governance rule connecting leakage control, interpretability, and asymmetric screening costs while preserving human oversight.

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Journal Info

Abbrev

IJEVSS

Publisher

Subject

Decision Sciences, Operations Research & Management Education Languange, Linguistic, Communication & Media Social Sciences Other

Description

International Journal of Education Vocational and Social Science(IJEVSS ) is  a peer-reviewed journal which welcomes submissions involving a critical discussion of policy and practice, as well as contributions to conceptual and theoretical developments in the field. It includes articles based on ...