Carbon tax better than cap-and-trade.
http://www.csmonitor.com/2009/0213/p09s01-coop.html
As my American Enterprise Institute colleagues Ken Green, Steve Hayward, and Kevin Hassett pointed out two years ago, "sudden changes in economic conditions could lead to significant price volatility in a cap-and-trade program that would be less likely under a carbon-tax regime."
Recent experience bears this out. Europe has in place a cap-and-trade program that today looks a little like the American mortgage-backed securities market – it's a total mess. The price of carbon recently fell – plummeting from over $30 to around $12 per ton – as European firms unloaded their permits on the market in an effort to shore up deteriorating balance sheets during the credit crunch.
It is this shaky experience with cap-and-trade that might explain an unlikely advocate of a carbon tax. Earlier this year, ExxonMobil CEO Rex Tillerson pointed in a speech to the problems with Europe's cap-and-trade program – such as the program's volatility and lack of transparency – as reasons he prefers a carbon tax.