Social Networks and Changes in Contraceptive use over Time: Evidence from a Longitudinal Study in Rural Kenya
Jere R. Behrman, Hans-Peter Kohler and Susan C. Watkins
Abstract: This study presents new estimates of the impact of social networks on changes in contraceptive use in rural Kenya, using special longitudinal household survey data collected explicitly for this purpose. Using an analytic model informed by a detailed knowledge of the setting, we find that: First, the estimates indicate that social networks have significant and substantial effects even after controlling for unobserved factors that may determine the nature of the social networks and that are not controlled in the previous literature. Second, controlling for unobserved factors that may determine choices of network partners, such as homophily, can substantially alter the estimated impact of networks, thus suggesting that failure to control for these factors may result in misleading interpretations. Third, the network effects are important for males, not just for females, and indeed may be stronger for males. Fourth, the network effects generally are nonlinear and asymmetric. In particular, they are relatively large for individuals who have at least one network partner who is perceived to be using contraceptives, suggesting that networks are primarily providing information through social learning rather than exerting social influence.