For no good reason, I was thinking recently about the problem of defining paternalism, of when a policy should or should not be considered paternalist. It occurred to me that there are at least three different arguments for regulations limiting what someone can do.
1. Bad for us. If what I do imposes costs on you, that's a reason why you might want to prevent me from doing it. An obvious example would be rules making vaccination compulsory.
2. Bad for you. What you do imposes costs on you; regulations will stop you from doing it, making you better off. That is paternalism. A recent example is the attempt by the mayor of New York to limit the size in which soft drinks can be sold on the theory that doing so will make people less likely to be obese. Cigarette taxes and restrictions on smoking fit the same pattern. The argument depends on assuming that the people making the regulations know what is good for other people better than they do, but most people do believe that they know what is good for some other people better than they do—those people who are doing things they are confident are bad for them.
3. Bad. From the standpoint of an economist, this is the most puzzling. A good example would be restrictions on male homosexuality. Such restrictions are common to many different societies. As best I can tell, the basic motivation is a gut level feeling that the activity is wrong—not bad for the person doing it, just wrong.
Practically any restriction can be, and is, defended on more than one of these grounds. The restriction on soda can be defended on the grounds that obese people impose costs on the rest of us in one way or another. Laws against homosexuality can be defended on the grounds that God doesn't approve of it and will punish the nation that permits it. Compulsory vaccination can be defended on paternalist grounds.
In most cases, one can get a pretty good idea of the real grounds of support for a policy by looking at what questions the supporters choose to look at. If the reason for trying to reduce obesity or smoking was to reduce external costs, you would think people would be interested in a realistic calculation of what those costs are. While doing things that reduces your life expectancy may impose costs on other people, it also reduces the amount of social security you collect, which is a benefit to other people. And it is not even clear that doing things that reduce your health increases total health costs—it might mean you die faster, with less expensive end of life treatment.
All of these would be relevant issues if the motivation were protecting us from you rather than you from you—but if you try introducing them into the argument you are unlikely to get a friendly reception. I recently came across an analysis
that concluded that obesity probably did not impose net external costs, but I do not expect it to persuade Mayor Bloomberg to change his policy. So far as the external costs of second hand smoke, a recent post
here described how careless supporters of a smoking ban on my campus were about the evidence to support their estimate of the size of the effect, which suggests that their real motive was paternalism.
Similarly for the case of homosexuality. People who want to ban it as a protection against divine wrath do not seem very interested in looking at the evidence for either God's opinion on the subject or the risk of divine punishment. For the latter they generally cite a single case from considerably more than two thousand years ago, ignoring both the ambiguity of the motive for the destruction of Sodom and Gomorrah—arguably the real offense was violation of the obligations of hospitality—and all of the societies since that have tolerated homosexuality and not been subject to a rain of fire and brimstone.
As to God's opinion, the evidence, at least in the case of Christianity, is not all that clear. The late John Boswell, a gay historian at Yale, argued pretty convincingly that both the scriptures and early Christianity for the most part treated homosexual sex as no worse than other forms of non-marital intercourse. Opponents of homosexuality may oppose heterosexual fornication as well, but rarely with the same passion. What convinced me that Boswell had a reasonable case, incidentally, was reading an attack on him by a prominent opponent which badly misrepresented the contents of the book I had just read; people who have good arguments do not need bad ones.
For a final and more ambiguous example, consider environmentalist regulation. It is frequently defended as a way of protecting us from each other, of keeping me from producing CO2 that will result in your house being flooded. But my conclusion from watching the arguments is that for many, perhaps most, supporters of such regulation that is not the central motivation.
Consider as evidence the issue of species extinction. People who argue that the extinction of a species will upset the ecology in ways that will impost drastic costs on us rarely offer much evidence for the claim, at least that I have seen, let alone enough evidence to justify the costs of protecting endangered species. People who argue that other species should be preserved because there may be information in their DNA that will at some future time prove informative to us do not, as a rule, react positively to the suggestion that the problem can be solved by preserving a few samples in liquid nitrogen for future genetic analysis, when and if doing so becomes appropriate. Large parts of the motivation, as best I can tell, are essentially religious, based on the feeling that natural is good. My category 3.