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Apr. 20: Micro-Structural Foundations of Network Inequality

  • 509 Knox Hall | Columbia University 606 West 122nd Street New York, NY, 10027 United States (map)

Micro-Structural Foundations of Network Inequality: Evidence from Observational Data and Field Experiments


WHEN: Tuesday, April 20, 2017, 1:00 - 2:30 p.m.

WHERE: Knox Hall 509, 606 W 122nd Street

Investigations of network inequality have long relied on the logic of preferential attachment, holding that newcomers to a social network prefer to form ties with central actors – who presumably are more valuable as network partners – rather than peripheral actors. We develop an alternative account to explain the emergence of network inequality that is based on local structural processes that do not require network actors to have knowledge about the social position of others.

Instead, we propose that central actors benefit from being exposed to more opportunities for triadic closure, which confounds the quality- or popularity-based signal that their greater connectedness might also send. After theorizing about our mechanism, we develop a simulation model to describe how triadic closure might cause network inequality. We then present results from an observational study and a field experiment across multiple professional conferences to disentangle an attendee’s network centrality from her opportunities for triadic closure as correlates of her tendency to form new ties.

In the field experiment, we compare a randomly assigned set of conference attendees for whom opportunities for triadic closure are highly visible to another set of attendees for whom such opportunities are obscured. The findings from this field experiment demonstrate that by minimizing exposure to possibilities for triadic closure, the tendency of already central actors to become even more central all but disappears. We discuss the implications of our findings for those who often find themselves at the periphery of a social network (e.g. racial/ethnic minorities and women).

Mathijs de Vaan is an Assistant Professor at the Haas School of Business at the University of California Berkeley. His research interests include social networks and health. One stream of his research involves field experiments that explore the formation of social networks and the effects of these networks on human behavior. A second stream of research examines how social networks in healthcare settings drive variation in the provision and consumption of healthcare. His webpage can be found here:

This event is free and open to the public. Lunch and light refreshments will be provided. All are welcome!

For inquires about Networks and Time, please contact coordinators Byungkyu Lee ( or Mark Hoffman (

Funding support for the Networks and Time Seminar Series is provided by the Paul F. Lazarsfeld Lecture Series, administered by INCITE, which features events and programming that embody and honor Lazarsfeld’s commitment to the improvement of methodological approaches that address concerns of vital cultural and social significance.