Figure 6.
Mean field social heterogeneity model. The flow diagram for the MFSH model (actual degree formulation). Because partnerships are durationless, partners do not change status while joined to a node; so there is no flux between the ϕ variables (a). The new variables πS, πI and πR (bottom, b) represent the probability that a randomly selected stub belongs to a susceptible, infected or recovered node. We can find πS in terms of θ and then solve for πI and πR in much the same way we solve for I and R in the configuration model. We then find that each ϕ variable is θ times the corresponding π variable. (Online version in colour.)