New Evidence on Trends in Vehicle Emissions
利用两个新的横截面数据库研究车辆排放特征，发现不同车型年份、品牌和尺寸的车辆排放差异很大，这对评估过去和未来车辆监管的效益有参考价值。
Aggregate vehicle emissions have fallen even though total miles driven have increased. This article uses two new cross-sectional databases to study vehicle emissions profiles. I find evidence of large differences in vehicle emissions across model years, makes, and sizes. These findings are relevant for evaluating the benefits of previous regulatory efforts and for predicting the benefits of further vehicle regulation.