Design And Analysis Of Incentive Strategies For The Evolution Of Cooperation In The Collective-risk Social Dilemma

Cooperation is common in human society and plays an important role in human de-velopment.However,cooperation is often undermined by selfish individuals,which make it difficult to emerge.The emergence and maintenance of collective cooperation has at-tracted the attention of experts and scholars in various fields.Related researches show that the collective-risk social dilemma game is more suitable to portray cooperative prob-lems.In addition,the introduction of punishment into collective-risk social dilemmas can change the situation in which cooperation is not easy to emerge for low risk.In addition to punishment,common incentive strategies include pure reward strategies and mixed incen-tive strategies.However,it is still unclear how the incentive strategy affects the level of collective cooperation.Therefore,this thesis studies the influence of incentive strategies on promoting the evolution of cooperation and explore the optimal incentive strategy that can effectively improve the level of cooperation under the framework of the collective-risk social dilemma game.Based on this,this thesis introduces a hybrid incentive strategy,referred to as executor,who can simultaneously reward cooperators who contribute to the public pool and punish defectors who do not make any contributions.This thesis studies how the incentive strategy affects the level of collective cooperation when the executor is rewarded and when the executor is not rewarded,respectively.The specific content is as follows:First,this thesis studies the evolutionary dynamics of cooperation in the finite popu-lation when the executor is rewarded.Specifically,this thesis considers the two situations of fixed and flexible incentive intensity.Furthermore,it studies the influence of incen-tive strategies on the evolution of cooperation when incentives are applied in the local scheme and in the global scheme.Results show that when incentives are applied in the local scheme,regardless of whether the incentive intensity is fixed or not,the pure re-ward strategy is always better than other incentive strategies in promoting the emergence of cooperation.In addition,when incentives are applied in the global scheme,and when the incentive intensity is not fixed,results show that pure reward strategy is the optimal incentive to improve the level of cooperation.Furthermore,this thesis reveals that ap-plying incentives in the local scheme is more effective in promoting the emergence of cooperation than applying incentives in the global scheme.Second,this thesis studies the evolutionary dynamics of cooperation in the finite population when the executor is not rewarded.Specifically,this thesis studies how co-operation in the population evolves when the incentive intensity is fixed and not fixed.In addition,this thesis studies the effects of mixed incentive strategies on the evolution of cooperation when incentives are applied in the local scheme and in the global scheme,respectively.Results show that regardless of whether the incentive intensity is fixed or not,whether it is applied in the local scheme or in the global scheme,the pure punishment strategy is the most effective incentive strategy to promote the emergence of cooperation,and show that applying incentives in the local scheme is more effective than in the global scheme to promote the emergence of cooperation.