Side Effects of Nudging: Evidence from a Randomized Intervention in the Credit Card Market
通过巴西金融管理平台的实地实验，发现信用卡还款提醒虽减少14%的滞纳金，却使透支费用增加9%，且对曾有透支历史的用户净增5%总费用，表明助推政策需考虑异质性影响。
Abstract This paper studies the direct and indirect effects of nudging, by means of a field experiment with a financial management platform in Brazil. Reminders for upcoming credit card payments reduced credit card late-payment fees by 14%, but increased overdraft fees in checking accounts by 9%. The unintended effect is concentrated in users with a history of overdraft use. These users experienced a net increase of 5% in total fees, while the rest experienced savings of 15%. The results provide clear insights for nudge design: like any policy action, nudges can have side effects, and one size may not fit all.