Abstract: To solve the environmental problems, the central government has formulated a series of environmental policies. However, in the process of implementation, the local government's behaviors decrease the implementation effect of Chinese environmental policies. Considering the dynamic change of pollutants, a Stackelberg differential game model is constructed to study the collusion between the local government and the enterprise in the process of pollution reduction. The analyses show that the degree of collusion between local governments and sewage enterprises is positively correlated with GDP preference of local governments, and negatively correlated with assessment of environmental performance. The different environmental responsibility systems have different effects on the collusion: if the local government is just responsible for the environment in the term of office, the local government may prefer to conspire with the enterprise; however, lifelong responsibility system can effectively restrain the collusion of the local government. The central government enhances the supervision and the cost coefficient of punishment can increase the collusion cost of the local government, which is the external constraint of the collusion between the local government and the enterprise. In order to restrain the impulse of the local government to collude with the enterprise, this paper puts forward some relevant advice: increasing the weight of environmental index in the achievement evaluation system of government, changing the traditional evaluation system, promoting the construction of the lifelong responsibility system for environment and implementing it actively; guiding the public to take part in the environment protection to make up for the lack of supervision from the central government; enlarging the punishment strength and combining the economic punishment with the political punishment to increase the cost of collusion between the local government and the enterprise.

Key words: pollution reduction, conspiracy, environmental policy, differential game

摘要： 考虑到污染物动态变化的影响,本文构建连续时间内地方政府和污染企业之间的Stackelberg微分博弈模型,对企业污染减排过程中的政企合谋问题进行研究。研究表明:地方政府和排污企业的合谋程度与地方政府的GDP偏好成正相关,与环境绩效的考核比重成负相关;不同的环境负责制对政企合谋的影响方向相反:任期负责制增强了地方政府的合谋动机,而终身负责制可有效地抑制地方政府的合谋动机;中央政府提高监督力度和惩罚成本系数增加了地方政府与企业的合谋成本,是抑制政企合谋的外在约束。为抑制政企合谋,应转变以GDP为核心的单维扭曲机制,推进建立生态环境终身负责制;积极引导社会第三方的环境参与,弥补中央政府环境监管的不足;多元化惩罚手段,将经济惩罚和政治惩罚相结合,提高地方政府和企业的合谋成本。

关键词: 污染减排, 政企合谋, 环境政策, 微分博弈