Stardate 20031004.1713

(Captain's log): I've been exchanging email with Philip about the Tragedy of the Commons (discussed in this post). He originally wrote:

I am sure that others have pointed this out but the standard solution to the TOTC is private ownership, where the owner is motivated to maximize the long term value and hence limits access to the property/asset.

To which I responded:

I'm well aware that this is how the libertarians propose to solve the problem, given that they despise the alternative (use of law enforcement). The problem is that in many cases it does not work. In many cases it cannot work.

Among other reasons, in some cases there's no obvious way to privatize ownership. In other cases there's no reason to assume that private ownership actually causes any motivation to maximize long term value.

And this is one of the reasons why I tell people that though I agree with the libertarians on a lot of things, that I disagree with them emphatically on some others and thus don't consider myself to be a libertarian.

He then wrote:

While I hang out at Libertarian sites, I also disagree with them on several issues, including law and order. The state should be allowed to coerce citizens for the collective good. I got involved in a thread at samizdata a couple of months back arguing that immunizations should be compulsory, because the value that accrues is highly dispersed, while the cost is directly and specifically to the individual. Its in the nature of epidemic diseases that if you immunize your child, you are helping (by a very small amount) to protect every child in the world. Not immunizing you child is classic freeloading.

My other big point of disagreement (and a current bugbear) is that IMHO they confuse freedom/liberty with privacy. For while Perry de Havilland and I were going head to head on this on regular basis. I have a longish unpublished article on the subject if you are interested (I doubt Samizdata would publish given their whiterose agenda :-( )

Finally back to the original topic. If I said the solution to TTOTC was private ownership then I should have said 'property rights'. There is no reason why the government or some other collective entity should not exercise property rights with the important condition that they act to maximize long term value. Something that despite good intentions, governments often fail to do. Offshore fisheries and the electromagnetic spectrum are good examples where government is really the only feasible entity to hold property rights. Although they should then auction (access to) those rights with conditions appropriate to maximize long term value.

When government uses laws to punish the kind of cheating which can lead to the Tragedy of the Commons, it actually is exercising property rights, in a sense. But for the Libertarians, the idea of using government coercion this way is axiomatically bad, since (capitalized) Libertarianism is a political movement built out of a relatively small number of basic axioms, one of which is that government regulation is always a Bad Thing.

Given that the use of criminal penalties against the cheaters seems to be the only way to keep it from happening in a lot of cases, Libertarians usually answer that it could also be prevented if property rights could be broadened, though that's usually presented as a philosophical claim without any details. On a few occasions I've tried to ask such people to fill in those all important details where the Devil lives, and have never gotten a coherent or convincing answer. I've concluded that it's dogma, similar to the kinds of dogma I hear from some religious types.

It turns out that they're wrong, because they're using too narrow an interpretation of "the commons", and because they assume that people who have property rights will invariably decide that maximizing long term yield is in their own self interest.

The problem is that the fundamental principle involved in the Tragedy of the Commons applies far more broadly than they give it credit for. Philip talks about immunization within the context of showing how he doesn't agree with the Libertarians about all things, but doesn't seem to realize that it's an example of a commons, though his arguments make clear that he dimly feels it intuitively.

When it comes to serious diseases for which vaccines are available, if you're properly immunized you can't get the disease. But even if you aren't, you can't get the disease if you're never exposed to it. There's what is known as "herd immunity", and what it means is that if everyone around me is immunized, I am also protected even if I was not immunized. Since no one I come into contact with can have the disease, I can never be exposed to it and thus cannot get it.

The chance of a disease spreading is a function of how likely it is that an infectious person comes into contact with and infects someone else (at least for most of the diseases for which vaccination is now controversial, with the notable exception of tetanus). If most of the population is immunized, people who are infected will not have many encounters w