Social Networks, Risk Perception, and Changing Attitudes towards HIV-AIDS: New Evidence from a Longitudinal Study Using Fixed-Effects Estimation

Stephane Helleringer, University of Pennsylvania

In this paper we compare the effects of social networks on the adoption of strategies to prevent HIV infection in Sub-Saharan Africa. We try to assess the mechanisms through which social interactions shape these behaviors (social influence vs. social learning). Using longitudinal data collected in rural Malawi (MDICP), we implement fixed-effects models to allow for the possibility that important unobserved characteristics of individuals or communities, determine not only the outcomes of interest but also the content and density of social interactions. We distinguish between social influence and social learning by analyzing data on the structure of networks in which conversations about HIV prevention occur. Our analyses emphasize the need to control for the non-random selection of network partners. Standard estimates without such controls are likely to misrepresent the effects of social interactions on the adoption of different strategies to prevent HIV infection.