Supplementary Material In this supplement, we provide additional details from the main paper. In Section 1, we provide two figures that illustrate the contagion/spreading process. In Section 2, we provide details regarding the empirical degree distribution and outcome models employed in Section 3 of the main paper. In Section 3, we formally specify the block structure used in the simulated contagion process in Section 4 of the main paper. In Section 4, we provide an expanded set of simulation results from Section 4 of the main paper. Figure 1: A schematic of the stochastic agent-based contagion process. Node j is shown in network (cluster) i . In this figure, red nodes are affected by the contagion, and black nodes are susceptible. Individual j is connected to k$_{ij}$ = 4 other nodes. The arrows represent the neighbors that might receive the contagion from an infected individual; the total number of arrows is the contagion affectivity of node j . Figure 1 shows a schematic of the contagion process for a specific node in a given network. Figure 2 shows the contagion process from its onset until study end. 1 Figures of the Contagious Process 20 j