Incentivizing Safer Sexual Behavior: Evidence from a Lottery Experiment on HIV Prevention

Incentivizing Safer Sexual Behavior: Evidence from a Lottery Experiment on HIV Prevention

By Martina Bjorkman Nyqvist, Lucia Corno, Jakob Svensson, Damien de Walque


Summary and Key Findings


An estimated 1.6 million new HIV infections occurred in Africa alone in 2013, adding to the nearly 25 million people living with HIV on the continent. New infections continue to outpace antiretroviral therapy uptake in most developing countries. Thus the global need for effective HIV prevention programs remains urgent. Lesotho is the country with the third highest HIV prevalence in the world, with over one quarter of the population and over 10 percent of young people (15-24 years) infected with HIV.  With such a high prevalence rate, effective behavior change strategies are desperately called for.


In this project we investigate whether the use of such financial incentives in the form of a lottery, conditional on remaining STI-free, can affect young individuals’ risky sexual behavior, and thus reduce HIV infection rates. The primary outcomes for evaluating impact will be (1) a subset of curable STIs (Sexually Transmitted Infection) that have been linked with risky sexual activity and (2) HIV prevalence.


We provide suggestive evidence that lotteries can be used to influence sexual behavior at relatively low costs. As a key constraint in scaling-up effective biomedical interventions, such as male circumcision, is low demand, and as financial incentive program are unlikely to be scaled up in low income countries unless the financial and administrative costs can be brought down, our results have clear implications for policy. We further show that a large share of the individuals that changed their behavior in response to the lottery program had a relatively high risk of getting infected by HIV. Targeting those with the highest risk of becoming infected is a key objective in HIV promotion programs. Such targeting is also important in many other types of prevention programs. Thus, our findings open up new avenues for future research.