IDOWU, G. A.; OWOLABI, J. E. ENSEMBLE-BASED FRAUD DETECTION IN NIGERIAN BANKING: A SYNTHETIC DATA BENCHMARK AND COST-SENSITIVE ANALYSIS GBOLAHAN ADENIRAN IDOWU∗ AND JOSIAH ENDURANCE OWOLABI ABSTRACT. Fraud detection in Nigerian banking is critically hampered by a scarcity of authen. Unilag Journal of Mathematics and Applications, v. 6, n. 1, p. 107 - 129, 9 Mar. 2026.