Meanwhile, Chris Bertram adds:

I have three reactions to this. The first is that McArdle’s description of the possible motivations for individuals is just absurdly simplistic: people either maximise their own good, or society’s, and since the latter suggestion is silly, we must work on the basis that of the former. Huh? How about intermediate possibilities, such as that people have a good that they try to realize, but that they also recognize constraints on the reasonable pursuit of that good (such as that other people have lives to live, have rights etc.). The second is that her justification for the self-interest assumption for states isn’t a simple consequence of her self-interest assumption for individuals. If individuals were straightforward maximizers of their own good then states would act in ways that reflect the self-interested action of the most powerful individuals within them rather than the (long term? short term?) interest of the state itself. Maybe there would be convergence, and maybe not, but McCardle isn’t entitled to the conclusion that states act self-interestedly on the basis that individuals do (if they do).

I have four reactions to this.

The first is that I wish people would spell my name correctly. There's only one "c" in McArdle . . . and also, for future reference, only one of each of the other letters. Given the dangerous resource shortages we may soon face as a result of overpopulation, I think we all need to be extra careful about wasteful letter mistakes.

The second is that his first point knocks down a straw man. I don't need to assume that people will only act in their self-interest--although clearly this is actually true for some values of the word "self-interest". I just need to assume that self-interest is a sufficiently powerful force that it will dominate other values in many interactions. This seems to me to be self-evidently true.

The third is that his second point is true, but not interesting; a definitional quibble. Obviously the governments of many countries are not acting to maximize the interests of all of the citizens of the country, and apologies to anyone who believed that when I said "states act in their own interest", I meant "Robert Mugabe does what is best for The People of Zimbabwe". He damn well doesn't. But that in no way refutes the notion that, in foreign policy, the government of Zimbabwe will generally be less concerned with the good of mankind than with the good of its own state--whether or not those interests happen to coincide with the collective interest of all the people now living within the borders of The Artist formerly Known as Rhodesia.

But his last point is where we really get to the heart of the argument, I think.

My third reaction is that, as Bruno Frey and others have argued, the self-interest assumption turns out to be a self-fulfilling prophecy. Design a system on the assumption that people will act to maximize their individual good and they will act on that assumption. They’d be crazy not to: why hold back from the trough when the rules of the game assume that everyone will be pushing their own snout forward? But this proves nothing fundamental. A system designed on the basis of a certain level of solidaristic or community spirit may well foster such attitudes, especially if we have effective mechanisms for punishing those who act greedily or selfishly.

This rather deftly ignores my point. A system in which we assume people will not act in self interest is a system which has no enforcement mechanism. Punishment mechanisms are what you build when you assume that solidarity and community spirit are not sufficient--which is exactly what I have been saying.

The problem with an international law model is precisely that there is no viable means of enforcement. Social punishment mechanisms work best in small homogenous groups where there is strong consensus about the relevant norms. This is not, I should say, a very good description of the global community right now, where about the only consensus I can see is that no one likes having less power than the US. This is enough consensus to fuel a movement to deprive the US of some of its power, but not to actually resolve many of the other thorny issues that are currently rending the world. Who shall we disinvite from the annual Stag Dinner in order to save Darfur?

That leaves force. Who shall provide it? Is it really reasonable to assume that America will submit to punishment from a body where it is the only real enforcement, in a case where America thinks that it has the right of the matter? Am I creating a self-fulfilling prophecy if I assume that America will probably not be willing to spend 4% of its GDP on a military it is not allowed to use without UN permission? And would the world actually be a better place without that spending? America might, which is precisely the argument that a lot of libertarians make; I'm pretty sure we can keep the Canadian and Mexican hordes at bay on a lot less than 4% of national income. But I think you have to think hard about all the knock-on effects from a decline in American military might before you conclude that this would be a boon for the rest of the world, too.

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