The Demand for and Impact of Learning HIV Status: Evidence from a Field Experiment

It is commonly believed that HIV testing is essential for disease prevention. Indeed, spending on counseling and testing accounts for over half of the total expenditures on HIV prevention in some African countries. Despite this, there is evidence that even when testing is available most people do not take advantage of it, and there is virtually no persuasive evidence on the behavioral response to knowing one's status. For this paper, I designed and implemented a randomized experiment to evaluate the demand for learning HIV results and to estimate subsequent behavior change. In the experiment, over 2,700 individuals in rural Malawi were randomly assigned monetary incentives to learn their HIV results after testing. Two months later, they were re-interviewed and given the opportunity to purchase condoms. I find that while less than half of the participants attended clinics to learn their HIV status without any incentive, even a very small incentive (about one-tenth of a day’s wage) increased the share learning their results by 50%. Using the exogenously assigned incentives and distance from results centers as instruments for HIV knowledge, I find that HIV positive subjects with a sexual partner who learn their status purchase significantly more condoms; however, the average number of condoms purchased is low. Using these estimates, I calibrate an epidemiological model of infection that suggests that HIV testing is not as cost-effective as other prevention strategies; however, if testing services already exist, offering incentives may more effectively avert new infections. ∗ e-mail: [email protected]; address: NBER, 1050 Massachusetts Ave, Cambridge, MA 02138; phone: (617)-588-0349; web address: www.people.fas.harvard.edu/~rlthornt. I am grateful to Randy Akee, David Cutler, Eliza Hammel, Richard Holden, Erica Field, Ed Glaeser, Emir Kaminica, Larry Katz, Michael Kremer, David Laibson, Sendhil Mullainathan, Ben Olken, Emily Oster, Michelle Poulin, Mark Rosenzweig, Jesse Shapiro, and participants at the Harvard Development and Labor Lunches for helpful comments and discussion. I thank Jere Behrman, Hans-Peter Kohler, Susan Watkins and the MDICP team for support and data and Kondwani Chavula for excellent assistance with fieldwork. The Malawi Diffusion and Ideational Change Project is supported by grants from the Rockefeller Foundation; NICHD (R01HD4173, R01 HD372-276); NIA (AG1236-S3); the Center for AIDS Research and the Center on the Demography of Aging at the University of Pennsylvania. The project on Information, Incentives and HIV/AIDS Prevention is supported by the University Research Foundation, University of Pennsylvania. Follow-up data is supported by the Warburg Foundation of the Economics of Poverty. I acknowledge financial support from the Harvard Population Center, Harvard Graduate Council, the Harvard Center for International Development, National Bureau of Economic Research Fellowship on Aging, and the University of Pennsylvania.