基于多主体成本分担博弈的流域生态补偿机制设计

Design of watershed ecological compensation mechanism based on multi-agent cost sharing game

建立生态补偿机制,是构建促进流域上下游之间协同维护生态环境安全的重要制度保障,是实现流域生态环境保护效益和经济效益的“双赢”的重要途径。文章基于微分博弈理论,构建了集中式生态补偿模型、无成本分担的分散式生态补偿模型以及引入成本分担契约的分散式生态补偿模型,讨论中央政府参与补贴与上下游选择分担污染治理成本行为之间的互动博弈策略,得出以上策略中流域上下游各自相应的最优反馈策略和污染治理量随时间变化的最优轨迹并加以比较。得出以下结论:①在有成本分担下的分散式决策中,由于上下游的博弈地位不同,两者所能获得的中央政府补贴系数也不同,处于领导者地位的将获得更大的治污减排补贴系数;中央政府的治污减排补贴政策改变了传统的三种博弈形式下流域成员的最优治污投入和流域经济收益大小关系,即中央政府的规制会使流域上下游地方政府采取不同的博弈形式来最大化自身的效益。②中央政府对地方政府的补贴使得上下游地方政府各自的治污减排投入水平、污染治理量、经济增长量达到三种策略里面的最高并与集中式策略相当,有效实现了流域生态补偿策略的协调。③在中央政府的协调下下游对上游给予合理的成本分担,才能使流域的经济增长实现帕累托改善,并且认为完善流域生态补偿机制的重点是完善横向与纵向相结合的财政转移支付机制。最后,通过具体的算例对相关参数进行了分析,验证了结论的有效性,为流域上下游长期开展协同生态补偿活动以及中央政府制定补贴政策提供了科学依据。

Establishing an ecological compensation mechanism is an important institutional guarantee to promote the coordinated maintenance of ecological environment safety between the downstream and upstream areas of the river basin,and an important way to realize the‘win-win of ecological environmental protection and economic benefits in the river basin.Based on the differential game theory,this paper constructs a centralized ecological compensation model,a decentralized ecological compensation model without cost sharing,and a decentralized ecological compensation model with cost sharing contract.It discusses the behavior of the central government s participation in subsidies and upstream and downstream choices in sharing pollution control costs.Based on the interactive game strategy between the above strategies,the corresponding optimal feedback strategies for the upstream and downstream of the basin and the optimal trajectory of pollution control over time are obtained and compared.The following conclusions are drawn:①In decentralized decision-making with cost-sharing,due to the different gaming positions of the upstream and downstream areas,the central government subsidy coefficients the two can obtain are also different,and the leader in the position will receive a larger pollution control and emission reduction subsidy coefficient.The government s pollution control and emission reduction subsidy policy has changed the relationship between the optimal pollution control input of the basin members and the economic benefits of the basin under the traditional three game forms,that is,the regulation of the central government will make the upstream and downstream local governments take different game forms to maximize their own benefits.②The central government s subsidies to local governments make the input level of pollution control and emission reduction,the amount of pollution treatment and economic growth of the upstream and downstream local governments reach the highest among the three strategies,and are equivalent to the centralized strategy,which effectively realizes the coordination of basin ecological compensation strategies.③Under the coordination of the central government,the downstream area should give reasonable cost sharing to the upstream area,so that the economic growth of the basin can achieve Pareto improvement.The key to the improvement of the ecological compensation mechanism is to improve the fiscal transfer payment mechanism horizontally and vertically.Finally,this paper analyzes the relevant parameters through a specific example to verify the effectiveness of the conclusions,which provides a scientific basis for the long-term collaborative ecological compensation activities in the upstream and downstream areas of the basin and for the central government to formulate subsidy policies.