4 papers
Interpretable vs Learned Encoders for High-Cardinality Fraud Detection
Xiao Han, Jingjing Liu, Moxuan Zheng +2
A total of seven categorical encoding methods were tested on the IEEE-CIS fraud benchmark dataset (590,540 records, 3.5% positives, 8 high-cardinality columns). The encoders were e…
How Early Is Early Enough? Design-Dependent Observation-Window Sufficiency in Subscription Churn Prediction
Xiao Han, Yao Xiao, Chenyu Wu +1
How many days of early behavior suffice for subscription churn prediction? In the public KKBox dataset, the early indicator of churn is typically an indicator of someone's contract…
Validation-Stage Combinatorial Fusion Analysis for Imbalanced Credit-Card Fraud Detection
Xiao Han, Chenyu Wu
Credit-card fraud detection is difficult because fraudulent transactions are rare, costly, and unevenly distributed. Strong gradient-boosted tree models already perform well on str…
Decomposing Firm-Level Crisis Responses from Incomplete Market Signals: Evidence from China's IT Sector During COVID-19
Xiao Han, Yao Xiao
Exogenous shocks generate heterogeneous behavioral responses across firms, yet event studies typically report only sector-level averages. This paper develops a multi-method approac…