Sending out an SMS: automatic enrollment experiments for overdraft alerts

At-scale field experiments at major U.K. banks show that automatic enrollment into “just-in-time” text alerts reduces unarranged overdraft and unpaid item charges 17% to 19% and arranged overdraft charges 4% to 8%, implying annual market-wide savings of £170 million to £240 million. Incremental benefits from “early-warning” alerts are statistically insignificant, although economically significant effects are not ruled out. Prior to the experiments, over half of overdrafts could have been avoided by using lower-cost liquidity available in savings and credit card accounts. Alerts help consumers achieve less than half of these potential savings.