Green Bank of Caraga held smokers' money hostage until a urine test proved they quit

In mid-2000s Mindanao nearly three in ten Filipino adults smoked, and the smokers in the study spent around 100 pesos a week on cigarettes — close to 15 percent of a month's income. Most wanted out: 72 percent said they hoped to quit someday, and 45 percent had tried within the past year. What the region offered them was information — pamphlets on smoking's dangers and tips for quitting, which alone moved almost nobody.

Rural banks sold savings accounts, not behaviour change, and nothing in the local landscape let a smoker put a price on their own resolution. Researchers Xavier Giné, Dean Karlan and Jonathan Zinman, working with Innovations for Poverty Action and the Green Bank of Caraga in Agusan del Norte, suspected the missing ingredient was not motivation but commitment — a way for the person who wanted to quit to bind the person who, in six months, would want a cigarette.

CARES — Committed Action to Reduce and End Smoking — was a voluntary savings account a smoker opened with a self-chosen deposit (50 pesos minimum, about a dollar), encouraged to top up with the money they would otherwise have spent on cigarettes. Six months later a urine test checked for nicotine and cotinine: pass, and every peso came back; fail, and the balance was forfeited to charity.

Let smokers stake their own money in a savings account, forfeited to charity if a urine test fails — loss aversion does the work willpower couldn't.

The deposit made an abstract resolution a concrete, owned loss.

Loss aversion did the work willpower couldn't at the moment of craving.

The urine test closed the self-report loophole; nobody can negotiate with cotinine.

Forfeiting to charity kept the penalty honest because the bank earned nothing from failure.

Passers got everything back, so the quitter lost nothing but the habit.

When people intend to persist but lapse, sell them a contract that makes failure cost them real money, verified objectively.

11% signed up; signers were 3 points likelier to be clean at six months — and still cleaner at surprise tests a year later.