When the typical economist tells me about his latest research, my standard reaction is "Eh, maybe." Then I forget about it. When Robin Hanson tells me about his latest research, my standard reaction is "No way! Impossible!" Then I think about it for years.
Case in point: Hanson's "Warning Labels as Cheap Talk: Why Regulators Ban Products." (Journal of Public Economics 87(9-10):2013-2029, September 2003) Simple version: Regulators typically have more "goody-goody" values than the public. Safety regulators care more about safety than most people; environmental regulators care more about the environment than most people. So what inference should the public draw if a regulator says "Not a good idea, but you're free to do as you please"?
Well, if even safety-obsessed regulators give you a choice, how bad could the choice be? If they really thought a choice was dangerous, they would forbid you to do it. This leads regulators to be even stricter than they want to be, because mere warnings are "cheap talk."
If this sounds odd, think about your parents (or kids). Parents put more value on kids' safety than kids' fun. So what should a kid think if mommy says "I don't approve, but it's your choice"? Well, if even mom doesn't forbid you to try, how bad could it be?
I don't think Robin has the whole story, but it did keep coming back to me. And then I had my house built, and learned that I had a choice to get a radon vent. The Hansonian logic was irresistible. "If even the EPA gives me a choice about the radon vent, the risk must be very small. So I don't want a vent."
Alas, now I've learned from Lomborg that indoor air pollution is a serious risk and radon is one of the most dangerous indoor pollutants. I'm not losing sleep over the problem, but if I had to do it over again, I think I would have paid for the vent. Which just leaves me wondering where Robin went wrong. I'll probably be thinking about it for years to come, if the radon doesn't get me first!