I keep meaning to write something substantive about the new EPA regulations on mercury and other toxins produced by America's oldest and dirtiest power plants, but instead for now let me just reply to Adam Ozimek on the timing of the new rules which I think is very good.
The rules, which apply to old power plants grandfathered in way back in 1977 under the assumption that they were nearing the end of their lifespan anyway, give violators 3-4 years to either deploy "maximum available control technology" or else shut down. This means that for any given plant you need to do the analysis of whether it's more economical to shut the plant down or to make the MACT investments necessary to keep the plant in business. What's good about the timing is that these next couple of years are an excellent time to have these investments made since given high unemployment and large-scale resource idling there will be less crowding out than there would be in ordinary times. At the same time, these next couple of years would be a terrible time for power plants to shut down and lay off workers, but the rule delays that happening for several years. So we'll get new investment in control technologies and replacement plants in the short term, with shutdowns and layoffs delayed several years out to a time when there will hopefully be less unemployment.
Now of course "good timing" is relative. In retrospect, letting these plants keep polluting for decades and then rather suddenly phasing them out through a top-down directive was a terrible idea. We could -- and should -- have been slowly ratcheting down emissions from these plants over the past 20-30 years and everyone would have been better off. But this is what happens when polluters insist on producing a very polarized political environment -- you get nothing nothing nothing nothing and then suddenly something.