Barkley Rosser, who is not held in the thrall of the Cato Institute, posts in the comments:
Maybe it's still early but this apparent gap in the literature is not encouraging. I'll repeat my query. What would be the climate benefits of this bill? If you want to cite an estimate involving strategic interdependencies with China and India, fine. But please cite something that puts forward and defends a particular estimate.
Is there a better case for this bill than: "it will raise government revenue, which I favor anyway, and raise the costs of unsavory corporations, which doesn't strike me as so terribly unjust anyway, and on the estimate of climate benefits I will just fudge it and hope for the best and claim we must do something?" David Frum comments.
Matt Yglesias has a different argument: better to start now than never.
I would phrase a related point more technically: acting now may be
keeping open a valuable option on doing more later. Still, I wish to
know what that option is worth, noting that if major action is impossible today it may be impossible tomorrow as well.
In the comments section of this post I'm not interested in being lectured about CO2 in the time of the trilobites, corrupt scientific groupthink, hearing that geo-engineering would be cheaper, or reading that various wimps won't face up to the need for nuclear power. I'm also not interested in hearing whether the costs of shifting to greener energy are high or low, at least not today. I just want to see the benefit estimates on this particular policy and if you put any serious estimate forward in due time I will assess it and report back to you.
Yes it is hard to model international interdependencies and option value — two of the major potential benefits — but we try to model such complexities for other policies all the time. Surely it's worth some group doing a 50-100 page study of what we can hope to achieve. Then we could see how plausible is the case for the bill.
If there is such a study, I promise I won't complain about the discount rate, I won't pretend that uncertainty militates in favor of inaction, and I won't dismiss it by saying a carbon tax would be better and then refusing to judge cap and trade vs. nothing. I want to see whether you need crazy or sensible judgments to get large aggregate benefits from proceeding.
Comments, of course, are open but subject to the above caveats. No trilobites!