Figure 2

Evolution of three strategies under the EI and EP mechanisms. Snapshots from (a) to (d) are steps 1, 100, 1000, and 3000 under the EP mechanism, respectively, and snapshots from (e) to (h) are steps 1, 100, 300, and 500 under the EI mechanism, respectively. Results accrued for \(r=2.0,\alpha =0.5,\beta =1.0\), and \(L=1000\) with prepared initial distributions. The rock-paper-scissors phenomenon in the EI mechanism allows the egoistic pool punisher to coexist with the other two strategies. While in the EP mechanism, the defector first eliminates the pure cooperator and the egoistic peer punisher eventually eliminates the defector.