From the lofty heights of Capitol Hill in Washington D.C., it may appear that the federal government makes all the important decisions about clean air policy. After all, US EPA regulations and the detailed provisions of the 1990 Clean Air Act regulate pollutants that float in the air, pollutants released by industrial and mobile sources (cars and trucks), and the type
of fines and sanctions levied against violators. From the Capitol Hill perspective, all these national standards and regulations are absolutely necessary. According to the cynics, if left to their own devices the states would adopt weaker and weaker environmental protection laws, creating a "race to the bottom" in which states compete for economic growth by enticing industry with less stringent - and less costly - regulations.