Research by economists from Duke University and MIT’s Abdul Latif Jameel Poverty Action Lab examines various strategies to prevent child marriages. It finds that providing financial incentives to delay marriage is most effective.

Bangladesh has one of the largest populations vulnerable to early marriage, with more than 15 million girls ages 10-19. Families often see early marriage as a financial necessity, which may help explain why numerous laws that prohibit early marriage and dowries have had virtually no effect in Bangladesh. Similarly, programs run by community groups that give adolescent girls life-skills and vocational training have had no impact in Bangladesh. So focusing on laws or empowerment will likely do less than 1 taka of good for each taka spent.

The analysis finds that the most promising program is one from southern Bangladesh that uses a conditional stipend to encourage parents to delay marriage for adolescent daughters.

From 2008-2010, the program gave cooking oil to parents of unmarried girls ages 15-17. Every four months, participants received four liters of oil—conditional upon a monitor confirming that they were still unmarried. A year’s supply of cooking oil costs Tk 1,250 per girl and aims to offset the economic burden of delaying marriage.

The modest financial incentive had significant effects. Recipient girls were up to 30 percent less likely to marry before age 16, and they were up to 22 percent more likely to remain in school. Each taka of spending on such conditional transfer programs does about 4 takas of social good.