Sacred Cars? Cost-Effective Regulation of Stationary and Nonstationary Pollution Sources
研究发现美国对汽车和发电厂的氮氧化物监管存在不对称，汽车减排的边际成本不到发电厂的一半，扩大监管范围可提高效率。
For political and practical reasons, environmental regulations sometimes treat point-source polluters, such as power plants, differently from mobile-source polluters, such as vehicles. This paper measures the extent of this regulatory asymmetry in the case of nitrogen oxides (NO x ), the most recalcitrant criteria air pollutant in the United States. We find significant differences in marginal abatement costs across source types: the marginal cost of reducing NO x from cars is less than half the marginal cost of reducing NO x from power plants. Our results measure the possible efficiency gains and distributional implications associated with increasing the sectoral scope of environmental regulations.