Ever been to Minneapolis? The state instituted a ridiculous self-defeating vehicle emmisions test program that was recently ditched. It was determined, even before the start of the program, that auto pollutants were decreasing. That didn't stop the west-office branch of the Kremlin, the Minnesota state legislature, from shoving the program through anyway. It was NEVER proved that the program contibuted to the reduction of smog (a problem we don't have anyway; nobody here even knows what the smog ratings used in other cities mean.) The worst offenders, the clapped-out 1979 T-birds with no catalytic converter (like my dad's) could trick their way through the tests with a couple gallons of isoproyl alcohol, and if that didn't work, they were given a waiver anyway.
Nobody here seems to have turned onto a simple principle of economics: the law of diminishing returns. Great advances have been made in the reduction of emissions over the last 20 years, to the point that one subcompact car from the mid-eighties puts out more pollution that several new Ford Excursions. As more time passes, the turnover of the nationwide fleet ensures that less and less of the old polluters are on the road. As vehicles get cleaner, however, the cost to continue to reduce new vehicle emissions becomes greater and greater. In other words, reducing airborne pollutants by 90% may cost the same as the next 5% reduction to 95%. A point is reached where the cost is much greater than the benefits. Take a look at the EPA's '97 edict that ground-level (0-2000 feet, I belive) ozone (smog) levels from .09 to .08 ppm. The projected cost was in the neighborhood of 9.6 billion, and the EPA's estimate on health benefits ranged from 1.5 to 8.5 billion. Clinton's economic advisors once put the estimate of health cost benefits at only 1 billion. Here's where the politics come in: the administration (and the EPA) disregarded an uncontradicted Energy Department report suggesting that because of the ozone's ultraviolet-blocking properties, reducing ground levels of it would result in 25-50 new melanoma deaths, 2-11 thousand new melanoma cases, and 28,000 new cataract cases each year. Clearly, the EPA, one of the biggest practitioners of junk science, wasn't interested in the cost or the facts.
It may everbody feel warm and fuzzy to say hey, why not reduce pollution that last 3 percent, with no reduction in performance levels? When a new Honda f4 costs $25,000, you'll know why.