Coordination and contagion: individual connections and peer mechanisms in a randomized field experiment

Philip Babcock, Kelly Bedard, Stefanie Fischer, John Hartman

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2 Citations (Scopus)


This paper investigates peer effects at the level of individual connections, leveraging the approach to shed light on peer mechanisms. In a field experiment using college freshmen, we elicited best friends and offered monetary incentives for gym visits to a treated subset. We find large spillovers from treated subjects to treated best friends but none from treated subjects to control best friends. We also find evidence of a mechanism: Subjects coordinate by visiting the gym with best friends, indicating that the intervention harnesses complementarities in utility or commitment mechanisms. Results highlight subtle peer effects and mechanisms that often go undetected.

Original languageEnglish
Article number104069
Number of pages14
JournalJournal of Public Economics
Publication statusPublished - May 2020
Externally publishedYes

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