U.S. Legislation Regulating Carbon: Cap and Trade or Tax?

The economist's take on the issue is in favor of a tax over a cap-and-trade system is given in the article below. Former Haas Dean Tom Campbell also agrees. His point is that the incentive to innovate never stops, and attempting to measure 1990 or some past year's levels is both impossible and arbitrary. I agree.

http://www.economist.com/opinion/displaystory.cfm?story_id=12562343