Anyway even if you want to live in Cass Sunstein land where everything is a cost benefit analysis then you have to work on some really hard problems like how it's not really possible to fairly cost something like a person getting cancer. It's also really hard to fairly compare them to the extremely diffuse "benefits", like the oil company doesn't need to spend a million bucks to install a scrubber so everyone's gas is 1 one trillionth cent per gallon cheaper on average.

Point is this kind of cost benefit stuff is a buck passing truism unless and until we can solve these problems and more. I won't be holding my breath.