农户环保合作的演化博弈分析

通过演化博弈理论分析农户环保博弈系统的演化过程与均衡状态, 首先建立复制者动态方程, 分析系统的演化稳定性; 然后讨论影响系统的随机因素, 在此基础上建立随机演化博弈模型, 分析系统的随机演化动态和随机稳定性。结果表明, 环保合作能否成为系统演化的结果, 取决于两方面: 1) 农户在考虑环保行为的成本、收益以及农户认为环保行为的正外部性给自身造成的损失后, 所得到的净收益; 2) 博弈过程的惯例。因此要促进制度向农户环保合作制度演进, 可以采取选择性激励措施, 增加采取环保行为农户的收益, 选择性激励措施的供给者承担制度变迁的主要成本; 同时建立行为重复机制, 使有记忆的博弈中环保合作成为唯一惯例, 行为重复机制的提供者承担制度变迁的主要成本。

Evolutionary Game Analysis on Environmental Cooperation of Rural Households

The process of institutional change that environmental cooperative state of rural households changing into environmental non-cooperative state of rural households comes with a cost. In the process, there is an environmental game played repeatedly by rural households. Here evolutionary game theory was used to analyze the evolutionary process and the equilibrium of the environmental game system. A replicator equation was developed to analyze evolutionary stability of the system. Then the source of stochastic disturbance which the process has suffered is analyzed. On this basis, stochastic evolutionary game model was developed to analyze stochastic evolutionary dynamics and stochastic evolutionary stability. Results show that whether environmental cooperation will become the result of the evolution depends on 1) taking into account direct costs and benefits along with losses caused by the positive externalities, environmental behavior is still profitable or not; 2) conventions of the game’s process. To promote current system changing to the system of rural households’ environmental cooperation, one way is to take selective incentives to increase payoffs of rural households who will take environmental behaviors, and those who provide selective incentives measures will commitment the main costs of institutional change; and another way is to establish action-repeating mechanism, making environmental cooperation become the only convention in recent past, and those who provide action-repeating mechanism will commitment the main costs of institutional change.