中文摘要：

本文利用2002年开始在六个省份实行的二氧化硫排污权交易政策所具有的“自然实验”性质，使用了基于全国省级面板数据的双倍差分模型，考察了二氧化硫排污权交易对单位产出二氧化硫排放强度的影响，研究结果发现二氧化硫排污权交易政策的实施确实降低了单位产出二氧化硫排放强度，同时也表明二氧化硫排污权交易政策在全国范围的推广具有重要的政策含义。

英文摘要：

Since 2002, the central government implemented the sulfur dioxide emissions trading policy in six provinces, using the ＂natural experiment＂ nature of this policy and the nationwide provincial panel data based on the double difference model, this paper analyzes the influence of sulfur dioxide emissions trading policy on Pollution intensity. The do reduce Pollution intensity, and it also show that policy implications in the nationwide promotion. study find that sulfur dioxide emissions trading policy sulfur dioxide emissions trading policy has important