Since 1970, transportation, power generation, and manufacturing have dramatically transformed as air pollutant emissions have fallen significantly. To evaluate the causal impacts of the Clean Air Act on these changes, we synthesize and review retrospective analyses of air quality regulations....

Taking advantage of the structure of the 1990 Clean Air Act Amendments (CAAA), we study the tradeoff between efficiency and equity associated with different levels of discretionary power when delegating regulatory authority to lower levels of government. Exploiting an instrumental variables...