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In real life, people often participate in regional public goods games and face the social dilemma caused by the non-exclusivity of public goods. Intervening policies are expected to alleviate the social dilemma and promote intra-regional cooperation. However, owing to the existence of the costs of policy, the marginal benefits of establishing intervening policies may be diminishing, which raises questions as to whether it is necessary to establish intervening policies on a global scale; whether partial intervention is a more economical solution. In view of this, this paper investigates the evolution of cooperation in regional public goods game in the context of a central institution selecting some regions to set up an endogenous reward and punishment policy, focusing on the effects of the proportion of selection and the methods of selection on global cooperation and total social welfare. The results show that the partial intervention is superior to the whole intervention in terms of total social welfare when the coefficient of the costs of the policy is large or when strict reward and punishment are imposed and that the partial intervention can achieve the effect of the whole intervention in terms of cooperation in many cases. For all three selection methods, i.e., random selection, degree centrality selection, and size selection, size selection is optimal in most cases. Furthermore, allowing groups in non-intervened regions to spontaneously establish or abolish the policy can greatly facilitate cooperation under all three methods. Finally, we find that the central institution's prolonged and sustained intervention is essential, and its termination will lead to serious consequences. • We explore the effect of partial intervention on global cooperation and welfare. • Groups in intervened regions establish an endogenous reward and punishment policy. • The roles of the three selection methods are discussed. • Partial intervention is more profitable than whole intervention in some cases. • Prolonged and sustained intervention is necessary. [ABSTRACT FROM AUTHOR]

"Friends of friends are friends, and enemies of friends are enemies" is a well-known friendship transmission effect. In interpersonal interactions, friendship transmission may prompt individuals to imitate one partner's attitude toward another. Real human interactive networks often show a high degree of clustering and are filled with triangles. In this context, friendship-transmission-based imitation (FI) may be very frequent and play a crucial role in the flourishing of cooperation. Here, we develop an evolutionary pairwise game model and conduct simulations on small-world networks with the aim of revealing exactly how FI affects cooperation. Specifically, we add four forms of FI to a strategy update framework with interactive diversity, using two sets of parameters to control the frequency of each update method. The results show that the different FIs play very different roles. Two of them even conditionally outperform the targeted imitation with reciprocal features. Furthermore, appropriate coexistence of multiple FIs may catalyze more cooperation. This work captures potential factors influencing the evolution of cooperation in real human societies, and contributes to understanding the drivers and the barriers to human cooperation in highly clustering interactions. • We focus on the mutual influence within triangle under interactive diversity. • A well-known friendship transmission effect is introduced in cooperation evolution. • Roles of four new strategy update methods are discussed separately. • Appropriate coexistence of different methods may promote cooperation. [ABSTRACT FROM AUTHOR]

For many years, social diversity has been recognized as one of the important factors in the emergence of cooperation. In PGG that characterizes collective social dilemmas, the difference in individual contributions to collective output usually arises from diversity of endowments and productivity, or from heterogeneous investments, but this difference may also be caused by the unequal dependence of collective output on members. In real collective actions, individuals may not contribute homogeneous currencies or goods, but instead divide labor to complete a series of tasks. Some individuals who master critical resources and skills may have a greater impact on collective output. In this work, a heterogeneous population containing elites and ordinary people plays spatial public goods game. The peculiarity is that ordinary people can make full contributions only when there are cooperative elites within the team. Otherwise, a part of the work will not be able to be carried out, and the cooperation contributions of ordinary people will be greatly reduced. Simulations under multiple social structures consistently show that the presence of a small number of elites can greatly stabilize cooperation. On the contrary, an excess of elites undermines the stable cooperative structure between elites and ordinary people. • We consider the unequal dependence of collective output on members. • A spatial public goods game involving elites and ordinary people is proposed. • There is an optimal proportion of elites that maximizes cooperation fraction. • Optimal value is not greatly affected by parameters but interactive structure. [ABSTRACT FROM AUTHOR]