Abstract: How to set the carbon tax rate? What factors enter into the decision? Are there differences among regions of big economy? This paper adds energy and carbon tax into aggregate production function, builds a dynamic optimization model in the environment constraints, solve the optimal carbon tax rate, and calculate it based on panel data of China. We find that, a series of positive influence factors and a series of negative influence factors, meanwhile the differences of optimal carbon tax among regions are significant. It means that the process of setting carbon tax rate must be under the principles of equity and common but differentiated responsibilities and respective capabilities.

摘要： 碳税最优税率如何确定？碳税最优税率受哪些因素影响？在区域发展不平衡的大国经济体中碳税最优税率是否存在区域差异？本文通过将能源要素和碳税效应引入总量生产函数，构建了一个环境约束下基于福利最大化的动态最优碳税模型，求解了最优碳税税率，并结合中国省际面板数据进行测算。研究发现人均总产出、居民对环境质量重视程度、人均能源消费、能源污染系数对最优碳税税率具有正向影响，环境质量、居民效用的时间折现率、碳税对资本和能源产出弹性对最优碳税税率具有负向影响。我国不同区域的最优碳税税率水平存在显著差异。结果表明，碳税开征初期应当实施税收优惠以避免对经济造成过大冲击，碳税税率确定应当遵循“共同而有区别的责任”和“各自能力”原则。