Guy Grossman—Peer Effects and Externalities in Technology Adoption: Evidence from Community Reporting in Uganda

Guy GrossmanJoin us
September 27
Monroe Hall 120

Join us for  Guy Grossman, University of Pennsylvania


Do social networks matter for the adoption of new political communication technologies? We collect complete social network data for sixteen Ugandan villages where an innovative reporting mobile platform was recently introduced, and show robust evidence of peer effects on technology adoption.

However, peer effects were not observed in all networks. We develop a formal model showing that while peer effects facilitate adoption of technologies with minimal externalities (like agricultural practices), it can be more difficult for innovations with significant positive externalities to spread through a network. Early adopters might exaggerate benefits, leading others to discount information about the technology’s value. Thus, peer effects are likely to emerge only where informal institutions support truthful communication.

We show that the observable implications of our model are borne out in the data. These impediments to social diffusion might help explain the slow and varied uptake of new political communication technologies around the world.


Guy Grossman is Associate Professor of Political Science at the University of Pennsylvania. His research interests fall under the broad category of political economy of development, with a regional focus on Sub-Saharan Africa and Israel-Palestine. In his work, he uses a host of causal inference tools as well as text and social network analysis to address substantive questions regarding political behavior, political development, and conflict processes. His work has appeared in the American Political Science Review, American Journal of Political Science, Journal of Politics, and International Organization among other journals.