Yesterday's post invokes a much broader, indeed nigh ubiquitous problem in public health, which is the tension, perceived or real, between promoting the general welfare, and liberty, which is a right that pertains to the individual. (Of course, one way to look at it is that individual liberty is part of the general welfare, so we are really talking about trying to balance competing welfare interests. I note this only to avoid getting bogged down in semantics.)

As it happens, this problem turned out to be a salient one in my weekly reading of medical journals this morning. In NEJM, James Colgrove discusses compulsory vaccination, in the specific context of the new HPV vaccine. In JAMA (subscription only, you inferior riff raff), David Kindig, in a somewhat puzzling essay, discusses the idea of a "pay-for-population health performance system."

As we have noted here before, there is something of a social movement challenging compulsory vaccination. 48 of the states allow parents to opt out on religious grounds, but many people campaign for other exemptions, some on philosophical grounds -- a simple assertion that liberty has priority, or a vaguely justified preference for "natural" or "alternative" methods -- and some maintaining that the consensus on the benefits of vaccination is factually incorrect. (Viz. the vaccines and autism scare.) The argument for compulsory vaccination does not have to depend on paternalism, however, because of what is called "herd immunity." If enough people are vaccinated, then people who cannot receive vaccinations due to medical contraindications, or who happen to be missed (such as recent immigrants or poor children who are historically at disproportionate risk of not being vaccinated) are protected. Hence your liberty to refuse vaccination may deprive someone else of liberty from sickness.

In the case of Human Papilloma Virus vaccine, however, this argument is somewhat attenuated, because HPV is a sexually transmitted infection, not transmitted by casual contact. Some parents believe they can teach their children to be abstinent until they enter a monogamous, lifelong marriage with a (presumably) similarly chaste partner. Therefore their daughter has no need for HPV vaccine and giving it to her undermines their moral authority. Of course, my response is that they are very likely to find they are mistaken in their expectations, but that's an empirical question.

Kindig's essay takes off from the movement to "pay for performance" in health care, in which doctors (or hospitals) would be paid more for following standards of care. He is interested in extending this concept to social determinants of disease, such as environmental quality, diet, etc., but the obvious question is, "Pay whom?" He never gets around to making that clear. But the relevance here is that so far, the effective methods we have found for promoting population health are mostly restrictive of liberty, or at least that's what their opponents say.

Smoking bans in public places, laws against drinking and driving, sanitary codes (e.g., you can't build a house without an approved septic tank, or linking to a sewer system and paying a monthly bill), health codes for restaurants and grocery stores, required food labeling, banning junk food in schools, banning advertising junk food to children -- all of these forbid some action, or require people to do something they might not want to do. Hence libertarians are skeptical, if not outright opposed, to many such measures.

It's easy to see that there is another side. The smoking ban in Boston has liberated me to go to restaurants and pubs without having to breathe toxic tobacco smoke. It's worth even more to the people who work there. Sanitary codes liberate us all from cholera and stench, and liberate our waterways from eutrophication and oxygen depletion. Labels on food products liberate me by giving me the power to choose what I want to put into my body. Etc. The point is that the liberty interest is almost never clear or straightforward, it is always a problem of balancing.

And therein lies the essential difference between liberalism and libertarianism. Liberals recognize that the state is not the only entity that can deprive us of liberty. So can business corporations, bullies, and just plain other folks who are careless or indifferent to other people's well being. We need civic order, organized by the state, to find our way through the intricacies of these tradeoffs.