SODAS lecture: Interaction between Multiple Layers of Networked Relationships and Implications for Diffusion

Title: Interaction between Multiple Layers of Networked Relationships and Implications for Diffusion

Abstract: People have relationships with others for many different reasons--for example, sharing advice and information, working together, borrowing and lending, etc.--a phenomenon called multiplexing. Using a dataset of about 30,000 households in 143 villages in Karnataka, India, we document some basic facts about multiplexing. There are significant correlations between different network layers, identifying a “backbone” social structure that is essentially orthogonal to standard network proxies such as geographic proximity or co-ethnicity. We demonstrate that statistics derived from the backbone network are strongly predictive of information diffusion. We show that multiplexing impedes simple contagions, but may enhance contagions of norms and behaviors that require reinforcement. Finally, we document how multiplexing varies by gender and wealth, potentially affecting information access.

Matthew O. Jackson is the William D. Eberle Professor of Economics at Stanford University and an external faculty member of the Santa Fe Institute. He was at Northwestern University and Caltech before joining Stanford, and received his BA from Princeton University in 1984 and PhD from Stanford in 1988. Jackson's research interests include game theory, microeconomic theory, and the study of social and economic networks, on which he has published many articles and the books `The Human Network' and `Social and Economic Networks'. He also teaches an online course on networks and co-teaches two others on game theory. Jackson is a Member of the National Academy of Sciences, and a Fellow of the American Academy of Arts and Sciences, the American Association for the Advancement of Science, the Econometric Society, and the Game Theory Society.