Regulating Untaxable Externalities: Are Vehicle Air Pollution Standards Effective and Efficient?

摘要本文研究不同于对污染征税的环境政策如何影响环境和福祉。该项目将重点关注新车的排放标准在多大程度上有效地减少了美国车辆的空气污染。该标准限制了不同地区空气污染物的每英里排放量。利用一系列数据，包括数千万辆新车和二手车的污染测试读数，该项目首先显示，自20世纪60年代以来，轻型车辆的空气污染排放量下降了99%以上。该项目将量化排放标准在多大程度上导致了这些减少，并研究车辆的排放是如何随着老化而增加的。最后，本研究将建立美国新车和二手车车队的分析和定量模型，以研究新车排放标准的变化和可行的替代政策如何影响社会福祉。这个项目更广泛的目标是促进对运输环境政策的效力和效率的认识。为该项目收集的微数据显示，自20世纪60年代监管开始以来，美国新车队每辆车行驶每英里的废气排放量下降了99%以上。回归分析利用不同年份、不同车型和污染物的新车辆排放标准的变化，来评估这99%的减排标准所带来的影响。初步分析记录了几个事实，这些事实共同表明，现有的标准并不具有成本效益：(1)车龄和里程解释了排放率的巨大差异；(2)少部分车辆造成了大部分污染；(3)基于车龄和其他车辆属性的政策比排放标准更能改善福利；(4)现有的清洁车辆注册费和财产税更高。分析还表明，这些事实并不适用于燃油经济性和二氧化碳排放，这一直是许多研究的焦点。本研究建立了车队的分析和定量模型，以研究可以补充标准的可行反事实政策。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

AbstractThis research studies how environmental policy that is different from a tax on pollution affects the environment and well-being. The project will focus on the extent to which exhaust standards for new vehicles, which limit the emissions rate per mile for different local air pollutants, have been effective at reducing air pollution from the U.S. vehicle fleet. Using a range of data, including tens of millions of pollution test readings for individual new and used vehicles, the project first shows that air pollution emissions from light-duty vehicles have fallen by more than 99 percent since the 1960s. The project will quantify the extent to which exhaust standards have caused these reductions, and study how a vehicle’s emissions increase as it ages. Finally, the research will build analytical and quantitative models of the U.S. new and used vehicle fleets to study how changes in new-vehicle emissions standards and feasible alternative policies affect the well-being of society.The broader objective of this project is to advance knowledge on the effectiveness and efficiency of environmental policies for transportation. Microdata compiled for this project show that for the major types of regulated air pollutants, exhaust emissions per vehicle mile traveled in the U.S. new vehicle fleet have fallen by more than 99 percent since regulation began in the 1960s. Regressions exploit changes in new vehicle emissions standards across years, vehicle classes, and pollutants to assess what share of that 99 percent decrease exhaust standards have caused. The preliminary analysis documents several facts which together suggest that existing standards have not been cost-effective: (1) age and mileage explain large differences in emissions rates; (2) a small share of vehicles account for most pollution; (3) policies based on age and other vehicle attributes improve welfare more than exhaust standards do; and (4) existing registration fees and property taxes are higher on cleaner vehicles. The analysis also shows that these facts are not true for fuel economy and CO2 emissions, which have been the focus of much research. The research builds analytical and quantitative models of the vehicle fleet to study feasible counterfactual policies that can complement standards.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.