One of the most hotly contested of all energy policy issues involves Corporate Average Fuel Economy (or CAFE) standards for new cars and light-duty trucks. Tighter standards would reduce gasoline consumption, and hence both greenhouse gas emissions as well as this country's vulnerability to oil...

About 45 years ago a few economists offered the novel idea of trading pollution rights as a way of meeting environmental goals. Such trading was touted as a more cost-effective alternative to traditional forms of regulation, such as specific technology requirements or performance standards. The...