Clunkers or Junkers? Adverse Selection in a Vehicle Retirement Program
利用加州尾气检查数据，研究车辆报废计划中逆向选择问题，发现计划成本效益随时间下降，而逆向选择持续存在。
Vehicle retirement programs have become popular tools of public policy for reducing pollution. The efficacy of these programs is difficult to measure, as it is difficult to tell how much a vehicle would have polluted otherwise. I estimate that counterfactual using data from a long-running local program in California. I utilize the universe of emissions inspections from the California Smog Check Program to construct vehicle usage histories of retired cars and similar vehicles which did not retire early. I find that the program's cost-effectiveness steadily declined over time because of the depreciation of the vehicle fleet, while adverse selection remained a problem throughout.