Fig. 4

The proportion of activities with hypothesized “top-down” and “bottom-up” violence. a The inferior gang is numerically less abundant at equilibrium, but persists through a higher activity spread rate (see Fig. 2a). The inferior gang is also subject to a greater proportion of “top-down” violence. b The inferior gang is numerically less abundant, but persists through a lower activity cessation rate (see Fig. 2b). The amount of “top-down” violence equals the amount of “bottom-up” violence. c The inferior gang is numerically less abundant, which is achieved through a lower activity spread rate and lower activity cessation rate (see Fig. 2c). In this case, “bottom-up” violence exceeds “top-down” violence