Frequency of Cooperators 0 0.5 0.2 0.4 0.6 0.8 1 0 0.5 0.2 0.4 0.6 0.8 1 0.3 0.2 α Values 0.1 0.4 0.3 0.2 α Values 0.1 Fine φ = 1 Fine φ = 1.25 Base Case (φ = 1.5) Fine φ = 1.75 Fine φ = 2 Cooperators for Different Fine φ Values (R = 1) 0.4 Base Case (R = 1) R = 1.25 R = 1.5 R = 1.75 R=2 Cooperators for Different Reward R Values (φ = 1.5) ΘL′ = 0.8; ΘH′ = 0.2 0 0 0 0.5 0.2 0.4 0.6 0.8 1 0 0.5 0.2 0.4 0.6 0.8 1 0.3 0.2 α Values 0.1 0.4 0.3 0.2 α Values 0.1 Fine φ = 1 Fine φ = 1.25 Base Case (φ = 1.5) Fine φ = 1.75 Fine φ = 2 Cooperators for Different Fine φ Values (R = 1) 0.4 Base Case (R = 1) R = 1.25 R = 1.5 R = 1.75 R=2 Cooperators for Different Reward R Values (φ = 1.5) ΘL′ = 0.5; ΘH′ = 0.5 0 0 Frequency of Cooperators 0 0.5 0.2 0.4 0.6 0.8 1 0 0.5 0.2 0.4 0.6 0.8 1 0.3 0.2 α Values 0.1 0.4 0.3 0.2 α Values Fine φ = 1 Fine φ = 1.25 Base Case (φ = 1.5) Fine φ = 1.75 Fine φ = 2 0.1 Cooperators for Different Fine φ Values (R = 1) 0.4 Base Case (R = 1) R = 1.25 R = 1.5 R = 1.75 R=2 Cooperators for Different Reward R Values (φ = 1.5) ΘL′ = 0.2; ΘH′ = 0.8 0 0 FIGURE 11 Analysis of the reward R (upper plots) and fine z (bottom plots) parameters based on a sensitivity analysis on a for three subjective audit probability scenarios (HlL = 0.8, HlH = 0.2 in the first column, HlL = HlH = 0.5 in the second column, and HlL = 0.2 HlH = 0.8 in the third column). We can see how the impacts of reward and punishment strategies depend on the scenario. Frequency of Cooperators Frequency of Cooperators Frequency of Cooperators IEEE COMPUTATIONAL INTELLIGENCE MAGAZINE | MAY 2021 Frequency of Cooperators 74