Evolutionary Dynamics Of Cooperation In Threshold Public Goods Games

From bridge building to the mitigation of global warming,improvement of cooperation in the threshold public goods provision has drawn many attentions.Some of simple mecha-nisms,e.g.money-back-guarantee,proportional rebate etc.have been brought in to improve the cooperation.However,current studies suffer from the problem of equilibrium selection.This paper offers an evolutionary refinement of multiple equilibria by studying the effects of three mechanisms on evolutionary dynamics:money-back guarantee(MBG),proportional rebate(PR)and uniform price cap(UPC).We find that MBG can insure a globally stable cooperative equilibrium,while PR and UPC can further improve cooperation at the stable state,and enhance the speed of reaching the equilibrium.We also extend the binary-action set to the triple-action set,and find that a full defection can be strictly dominated by interme-diate actions that are between a full defection and a full cooperation,and show the presence of intermediate actions can significantly improve cooperation.Finally,in the long run with occasional mutations,we prove that population will converge to a unique and efficient state where provision always succeeds.