Figure 4: The competition between different types of social exclusion and costly punishment in the optional PGG.
From: Competitions between prosocial exclusions and punishments in finite populations
When strategies can penalize defectors only, shown in panel (a), then all strategies coexist in time average for weak strength of imitation, but in most of the time peer excluders form the majority of the population for other imitation strength values. Panel (b) shows the case when second-order sanctioning is possible. Here pool excluders prevail and conquer the whole population. Parameters: N = 5, r = 3, c = 1, μ = 10−6, σ = 1, M = 100, cE = δ = 0.4, β = γ = 0.4, and B = G = 0.4.
