Peer effects in marathon racing: The role of pace setters

Abstract Marathon races are rank-order tournaments with prizes determined primarily by relative performance. As a result, peer performance is an important determinant of an individual's performance. Peer effects have been extensively studied in a variety of settings, with much of the research concerned with finding a measure of peer performance that is exogenous. We focus our research on marathon races with pace setters as their presence allows for us to identify exogenous peer effects by identifying variation in peer performance and ability that is exogenous. Using data on elite male runners from 2009 to 2014 marathons in Berlin, Chicago, and London, we find the presence of negative exogenous peer effects and this result is robust to a number of peer performance variables. We attribute our result to the self-sorting of runners by ability and the subsequent invidious comparison that occurs in marathons with pace setters.