Sample size: planned number of clusters
For the purposes of randomization, we formed clusters of individuals based on information that a small number of participants knew each other. We placed individuals who reported knowing each other into the same cluster, such that they would always receive the same treatment assignment. There are 20 of these clusters (18 clusters of 2 individuals and 2 clusters of 3 individuals), as well as 2,958 individuals who are considered their own cluster.