On the volokhconspiracy, my colleague Todd Zywicki has a little piece on auto safety before and after NHTSA’s creation in 1970. It has a graph suggesting (though, Todd notes with excess caution, not showing) that NHTSA has made little if any difference. I use graphs of this sort when I teach State Farm (1983), the famous “airbags case” in which the Supreme Court took a “hard look” at NHTSA’s regulation—alas, without the slightest comprehension of what it was doing. I even happen to know the rate of decline in fatalities per passenger vehicle miles: 3.5% per year in the decades preceding NHTSA; 3.5% thereafter.
There is a rich literature on the subject, beginning with a 1975 study by Sam Peltzman. People, Peltzman argued, don’t behave like crash dummies: regulate, and they change their behavior (e.g. by driving more recklessly); and the response is big enough to wipe out the expected safety gains. That finding has held up pretty well, and you get a “Peltzman effect” and very similar results regardless of what you look at—drug safety and “effectiveness,” workplace safety, child labor, even the environment. This is a depressing performance, especially considering the cost of regulation. Alas, it’ll continue.