Six SQL patterns for detecting transaction fraud in benefit programs

Summary

A data professional on a program-integrity team shares six practical SQL patterns for detecting transaction fraud in government benefit programs. The patterns cover velocity checks (rapid successive transactions), impossible distance calculations (geographic anomalies), suspicious amount detection (round numbers, just-below-threshold amounts), merchant cluster analysis (linked merchants), off-hours transaction flagging, and window function techniques for pattern recognition. The article emphasizes that SQL remains the most effective tool for fraud detection, more so than machine learning or specialized databases, and provides concrete query examples that can be adapted to any transaction-based system.