跨界污染情形下贸易自由化对均衡污染税及社会福利的影响

摘要

本文构建了一个基于相互倾销贸易理论的两阶段双寡头模型，并考虑了两种形式的污染损害函数，分析了跨界污染情形下贸易自由化对均衡污染税以及社会福利的影响。本文的结果依赖于选定的污染损害函数的形式。在线性污染损害函数的情形下，贸易自由化会导致均衡污染税下降，并且社会福利与关税之间呈倒“U”形关系。在二次型污染损害函数的情形下，结果取决于污染跨界系数与污染损害系数的值：当污染损害系数足够小时，贸易自由化总会导致均衡污染税下降；当污染损害系数足够大时，贸易自由化总会导致均衡污染税提高。而当污染损害系数适中时，贸易自由化既可能导致污染税提高，也可能导致其下降，结果取决于污染跨界系数的值。%Based on the Reciprocal Dumping Theory , this paper builds a two stage duopoly model with the consideration of two forms of pollution damage function , and analyzes the effects of trade liberalization on the equilibrium pollution tax and social welfare in the case of transboundary pollution .The results depend on the form of pollution damage function chosen in this paper .In the case of linear damage case , trade liberaliza-tion decreases the equilibrium pollution tax , and the shape of social welfare is inverted -U with regard to the tariff.But in the case of quadratic damage , the results rely on the values of transboundary pollution coefficient and pollution damage coefficient .When the pollution damage coefficient is sufficiently small , the trade liberal-ization always decreases the equilibrium pollution tax .When the pollution damage coefficient is sufficiently large, trade liberalization always increases the equilibrium pollution tax .Moreover, when the pollution damage coefficient takes intermediate values , trade liberalization either increases or decreases the equilibrium pollution tax, and the results reckon on the values of transboundary pollution coefficient .