Paying people to avoid sexually transmitted diseases effectively reduces their spread, according to a proof-of-concept study carried out by scientists at UC Berkeley, the Development Research Group at the World Bank and the Ifakara Health Institute in Tanzania.
The study involved young adults in southwestern Tanzania. Subjects were randomly assigned to a high-payment group, a low-payment group and no-payment control group. Participants in the high payment group received $20 every 4 months–up to $60–if they tested negative for STDs. Those in the low-payment group received half that amount.
Participants in all groups received individual counseling and could attend monthly group counseling sessions as well. Any participant that tested positive for an STD received free care for the condition.
By the end of the year, 9% of participants in the high-payment group had tested positive for an STD. That was significantly better than the 12% rate seen in both the control group and the low-payment group. The cash reward had the same impact in men and women. It had a more pronounced effect in people with lower incomes.
“For many of our study participants, $60 represented about one-fourth of their reported annual income, so it was a significant incentive,” says Will Dow, a study author and a health economist at Berkeley. “The question we tested is whether the cash reward was enough of an incentive to reduce risky behavior. The fact that disease prevalence decreased suggests the incentives worked.”
Participants were tested for chlamydia, gonorrhea and syphilis. HIV/AIDS status was not tested, but the same sexual behaviors that increase the risk of the STDs increase the risk of HIV.