David Friedman on the Precautionary Principle
By David Henderson
In the mid to late 1980s, I used to do 5 or 6 book reviews a year for Fortune magazine. My editor then was the late Dan Seligman, a legend at Fortune. He was the most economically literate journalist I had met until that time. And since then, I still haven’t met anyone quite as good.
He is also the person who, more than anyone else with the possible exception of my wife, taught me how to write well.
Dan published about 85% of the reviews I sent him. Unfortunately, one he didn’t publish was my review of David Friedman’s 2nd edition of The Machinery of Freedom. I’ve forgotten why; my vague recall is that he thought the subject wouldn’t interest enough of his readers. When Dan and I were reminiscing in the early 1990s, he told me his biggest mistake with me was not publishing my review of Barbara Branden’s The Passion of Ayn Rand. His reason: he later realized just how many Fortune readers were interested in Ayn Rand. I replied that his biggest mistake was not publishing my review of Richard Epstein’s Takings and his second biggest mistake was not publishing my review of David Friedman’s Machinery.
I remembered all this this morning when I checked out David Friedman’s blog and noticed that he is posting some new chapters for his 3rd edition of Machinery. The one I read is excellent. It’s titled “The Conservative Mistake.” The chapter is very short: you can probably read and grok it in 2 minutes or less. One highlight is his discussion of the Precautionary Principle, which, like so much of David’s writing, hits the nail on the head with only a few words. It’s actually better than the discussion by Aaron and Adam Wildavsky in “Risk and Safety,” in The Concise Encyclopedia of Economics.
The left wing version of the conservative mistake comes with its own pseudoscientific slogan, “the precautionary principle.” It is the rule that no decision should be made unless one can be confident that it will not have substantial bad effects, that the lack of any good reason to believe it will have such effects is not enough. At first glance it sounds plausible, but a moment’s thought should convince you that it is internally incoherent. The decision to permit nuclear power could have substantial bad effects. The decision not to permit nuclear power could also have substantial bad effects. If one takes the precautionary principle seriously, one is obligated to neither permit nor forbid nuclear power and similarly with many other choices, including acting or not acting to prevent global warming.
By the way, David posts his chapters so that he’ll get feedback. Obviously I like the chapter a lot. My one nit-picky piece of feedback is that in the third paragraph, the sentence, “The first is that human habitability is limited mostly by cold not heat” should have a comma after “cold.”
P.S. In looking at my earlier post on Seligman, I noticed that I promised to tell my story about first writing for him. The body blow I took from his first edit was one big step on my path to good writing. I’ll tell the story sometime in December.