I asked Professor Miguel about his in-progress work concerning social networks and learning about health in Kenya. Up until recently, Professor Miguel said, economists have concentrated on solely economic models, but economists are now beginning to recognize the importance of sociological models as well. Professor Miguel is now asking new sociological questions about a past project in which Kenyan students were treated for helminthal infections. He and his colleagues are constructing social networks by computing how many people are choosing to get treatment, and then looking at how likely others are to get treatment. The idea here is that one could get treated because everyone else in your peer group is getting treated, but one could also get treated because you have always had health-conscious friends. In the latter case, the peer group does not have a causal effect on your behavior.

Preliminary results of the study show that people who had friends who participated in the treatment are actually less likely to get treatment – an unexpected result. Now Professor Miguel is looking at possible side effects of the drugs; perhaps people forgo long term benefits of better health to avoid short term side effects such as vomiting. Another issue is externalities; people could free-ride when their friends are treated, if they observe the positive externalities of a community’s better general health. In this case, the researchers must separate health externalities from information externalities. Again, as they are still collecting a lot of data, these results are still preliminary.

 Professor Miguel noted that both economic models, which concern the individual, and sociological models, which concern the society, are important in analyzing people’s behavior. In past studies, people do tend to follow sociological herding models, in which people follow the crowd, often