You state: "A carbon tax, he said, would be simple and fair and speed the transition to a clean-energy economy. By contrast, he said, a cap-and-trade system inevitably would be overly complicated....

Anyone who’s paid even cursory attention to the Congressional debate over climate change knows that Hay was absolutely right."

Why do you think a carbon tax wouldn't be politicized, heavily lobbied, and also evolve into a complicated system? And you really think everyone would clap and agree that it was fair?

It's time to start putting good public policy before political expediency. A carbon tax--by almost everyone's admission--is the better solution to global climate change. And this is an important enough issue that we should not allow our lawmakers--or our opinion leaders, for that matter--to bow to political pressure at the expense of the best possible outcome.

I second the previous poster. What planet do people live on where they think a carbon tax would not be "overly complicated, negotiated in Washington back rooms, subject to political horse-trading and shaped not by the public good but by special interests"?

The difference with cap and trade is that all the wheeling and dealing is mainly about reallocation of resources. Proposals to weaken the cap are transparent and obvious. With a carbon tax, the backroom deals and exemptions would directly undermine its efficiency and environmental effectivness. At the end of the day, we'd have no idea how effective it would be at reducing emissions until after the fact, and recalibrating the tax to "get things right" would be another political nightmare. Have you seen the U.S. tax code? Only ivory tower economists could support a tax in practice.