economics Practical Magic

People will happily take way less interest on their money if you can just prove it isn't fake.

SSRN · March 18, 2026 · 6340238

Qi Li

The Takeaway

By modeling e-commerce fraud, researchers found that the 'recognizability' of a currency is more valuable than its interest rate. People are so sensitive to the risk of being cheated that they will accept a significantly lower return on their assets just to use a system with slightly better fraud detection.

From the abstract

This paper studies the welfare consequences of imperfect payment recognizability in a monetary search model. Sellers observe a noisy signal of payment authenticity and choose acceptance thresholds that balance fraud losses against the rejection of legitimate payments. The information structure maps directly to the ROC--AUC statistic used to evaluate fraud detection systems, linking modern payment technology to monetary theory. Calibrating the model to e-commerce payment fraud statistics, seller