A couple weeks back, Steven Levitt admitted a moral shortcut:
If the answer is that I wouldn’t want my daughter to do it, then I don’t mind the government passing a law against it. I wouldn’t want my daughter to be a cocaine addict or a prostitute, so in spite of the fact that it would probably be more economically efficient to legalize drugs and prostitution subject to heavy regulation/taxation, I don’t mind those activities being illegal.
The fact that I would want to be able to involve the police if my daughter became a streetwalker, but not if she became a Hari Krishna, tells me something important about what kind of legal regime I should support. (There’s a touch of Kantianism in it: One’s (legal) preferences for one’s daughter should become a universal law …) And the fact that Wilkinson disagrees doesn’t prove that he believes in logic and reason, whereas I believe in raw emotion. It just proves that his answer to the daughter test is — for now, at least — different from my own.
Wilkinson came back at him:
It's true, as Mr Douthat concludes, that my answers to the daughter test are different from his. But my argument against prohibitions on drugs, gambling, abortion and prostitution is not that these restrictions do not fail my daughter test. My argument against them is that they fail the test of public justification, that many of us have perfectly reasonable grounds for rejecting and resisting the imposition of these constraints. … We are, all of us, a confusion of sentiments. The advance of liberal civilisation consists in no small part in unwinding the tensions between our liberal and illiberal impulses.
Kevin Drum put the entire debate in perspective:
There are lots of activities we AP-class types find acceptable — drug use, gambling, etc. — because we sort of assume that everyone has the same level of impulse control that we do. And if you have good impulse control, then drugs and gambling are just pleasant ways of filling in your free time. … But if you're not part of the AP-class cohort, there's a pretty good chance that your impulse control isn't quite as good as all that, and an excellent chance that even if it is, you're keenly aware that good impulse control isn't exactly universal.