Put Your Money Where Your Butt Is: A Commitment Contract for Smoking Cessation
设计并测试了一种自愿承诺产品（CARES），让吸烟者存入资金6个月后通过尿检，若戒烟成功则返还资金，否则捐给慈善机构。结果显示该产品显著提高了戒烟成功率，且效果持续至12个月。
We designed and tested a voluntary commitment product to help smokers quit smoking. The product (CARES) offered smokers a savings account in which they deposit funds for six months, after which they take a urine test for nicotine and cotinine. If they pass, their money is returned; otherwise, their money is forfeited to charity. Of smokers offered CARES, 11 percent took up, and smokers randomly offered CARES were 3 percentage points more likely to pass the 6-month test than the control group. More importantly, this effect persisted in surprise tests at 12 months, indicating that CARES produced lasting smoking cessation.