Peer influence and social interactions can give rise to spillover effects in which the exposure of one individual may affect outcomes of other individuals. In an empirical evaluation of the effect of a school-wide intervention on reducing individual students’ depressive symptoms, we provide a framework that can accommodate issues of mediation and spillover effects in group randomized trials.
VanderWeele, T., Hong, G., Jones, S., & Brown, J. (2013). Mediation and spillover effects in group-randomized trials: A case study of the 4R’s educational intervention. Journal of the American Statistical Association.