On efficiency grounds, the economics community has to date tended to emphasize price-based policies to address climate change -- such as taxes or a “safety-valve” price ceiling for cap-and-trade -— while environmental advocates have sought a more clear quantitative limit on emissions. This...

Total pollution emitted by U.S. manufacturers declined over the past 30 years, even though manufacturing output increased. This improvement must result from one of two trends: (1) changes in production or abatement processes (“technology”); or (2) changes in the mix of goods manufactured in...