Local air pollution from vehicles is an enormous global problem, yet vehicle emissions policies are under‐studied and their effectiveness is not well‐understood. Emissions standards for new vehicles are ubiquitous, but a substantial share of pollution is emitted by old vehicles with broken emissions control equipment. Smog check programs target those older cars, but are administratively costly and believed to trigger mostly short‐lasting repairs (Merel et al., 2014). This project aims to measure how effective these existing policies are in reducing vehicle emissions, and predict which alternative policies could lead to more and cheaper emissions reductions.
The project will be able to rank many different existing and newly proposed vehicle emission control policies, in a way that policy makers will find it easy to understand. Given the current (surprising) lack of knowledge about how vehicle emissions control policies perform, this study will hopefully be a timely and much‐needed example of how scientific research can provide direct and actionable policy guidelines.