Fig. 4

Increasing β_B with τ_A=0 and a low τ_B=0.02. When β_B is low (a), Contagion B diffuses more slowly than A. However, as β_B increases in (b), even when Contagion A still diffuses faster its diffusion depth has lowered. When β_B>β_A (c), then Contagion B diffuses more rapidly and lowers the diffusion ceiling of Contagion A. When β_B is high (d), Contagion A barely diffuses. α was fixed to 1.0