The role of selection in socioeconomic homophily: Evidence from an adolescent summer camp

Socioeconomic homophily in friendship networks is the result of several co-occurring processes, which are extremely challenging to disentangle. We propose to study the particular context of a three-week summer camp in France that gathered teenagers from varied socioeconomic backgrounds. We argue that this camp provides a unique opportunity to observe the sociability of adolescents in well-bounded settings with equalized meeting opportunities, thus helping us to narrow down the specific role of homophilic selection - the process by which individuals actively select similar friends. We use Stochastic Actor-Oriented Models to analyze the declared friendships of participants. Furthermore, we introduce a novel longitudinal extension of the Exponential Random Partition Model (ERPM), a model developed for relational data organized in discrete groups, which we apply to observed meal-sharing among adolescents. Results point to weak to non-existent homophilic selection during the stay. In turn, this suggests that structural opportunities and contextual moderators might be essential in explaining the amount of socioeconomic homophily found at school or in other contexts.