Detecting Spillover in Social Networks: Design and Analysis of Multi-level Experiments

Wednesdays@NICO Seminar, Noon, January 26 2011, Chambers Hall, Lower Level

Prof. Betsy Sinclair, University of Chicago


Interpersonal communication presents experimental researchers with a methodological challenge and a research opportunity. The challenge is that communication among subjects blurs the line between treatment and control conditions. When treatments are transmitted from subject to subject, the Stable Unit Treatment Value Assumption (SUTVA) is violated, and comparison of treatment and control outcomes may provide a biased assessment of the treatment’s causal influence. Social scientists are increasingly interested in the substantive phenomena that lead to SUTVA violations, such as communication in advance of an election. Experimental designs that gauge SUTVA violations provide useful insights into the extent and influence of interpersonal communication. This paper illustrates the value of one such design, a multi-level experiment in which treatments are randomly assigned to individuals and varying proportions of their neighbors.  


I am an Assistant Professor in political science at the University of Chicago. My research interests are located in American politics and political methodology with an emphasis on individual political behavior. I focus on the social foundations of participatory democracy-the ways in which social networks influence voting, donating, choosing a candidate or identifying with a particular party. I received my PhD from the California Institute of Technology in 2007 and my BS from the University of Redlands in 2002. More information can be found at