Protocols for Randomized Experiments to Identify Network Contagion

• Activity Number: 525
• Type: Topic Contributed
• Date/Time: Wednesday, August 12, 2015 : 10:30 AM to 12:20 PM
• Sponsor: Business and Economic Statistics Section
• Author(s): Andrew C. Thomas*
• Companies: University of Florida
• Keywords: networks ; experiment ; contagion ; homophily

Abstract

Identifying the existence and magnitude of "social contagion", or the spread of an individual trait along ties in a social network, is a challenging task due in part to the tendency of individuals with similar characteristics to connect, also known as homophily. While randomized experiments on individuals of a network would seem to be the ideal method for establishing contagion, there are still considerable methodological issues stemming from structural considerations, including the likelihood of inclusion in the sample group and the implicit dependence between units due to latent homophily. We construct a protocol that correctly adjusts for these factors in a number of experimental situations.