Social Network Influences and AIDS Risk Perceptions: Tackling the Causality Problem

Hans-Peter Kohler, Max Planck Institute for Demographic Research

Understanding the determinants of individuals' risk perceptions about AIDS is an essential step towards curtailing the spread of this disease. We develop a theoretical model of learning and decision-making about AIDS with a focus on uncertainty, and argue that social interaction is an important determinant of risk perceptions and behavioral change. Using longitudinal survey data from rural Kenya, we test this hypothesis and investigate whether social interactions - and especially the risks perceptions of social network partners - exert causal influences on respondents' risk perceptions and spousal communication about AIDS. The study explicitly allows for the possibility that important characteristics, such as unobserved preferences or community characteristics, determine not only the outcomes of interest but also the size and composition of networks. The most important empirical result is that social networks have significant effects on risk perception and the adoption of new behaviors even after controlling for unobserved factors.