When The World Bank Becomes The Sugar Daddy

The organization is experimenting with cash allowances as a way to slow the spread of AIDS in Africa, where "relationships between older men and younger women are one of the main transmitters of HIV":

In some areas, which acted as controls, the [never-married women between the ages of 13 and 22] were simply monitored. In some they and their parents were given small amounts of money each month (between $1 and $5 for the women, and between $4 and $10 for the parents), again decided at random by the computer. In a third set of areas money was doled out in a similar way, but only in exchange for a promise by the woman to attend school. If she failed to do so, no money was forthcoming. 

When the results were in, the team found that the unpaid women had suffered more than twice the HIV infection rate experienced by the paid women over the course of the 18 months of the experiment, and four times the infection rate of genital herpes. Intriguingly, there was no difference between the infection rate suffered by those required to go to school and those who received the money unconditionally. … [The women given money] had younger boyfriends than those in the control group, and had sex less frequently. Liberated from the need to find a sugar daddy, they could behave in a safer way.