I mostly agree with Will that our long-term goal in immigration policy should be “the best feasible approximation of a single global labor market–a world in which people are free to travel the world in search of the most valued use for their skills.” Although I’d broaden it a bit and leave out the part about labor markets: I think people should be free to travel the world in search of education, entertainment, cultural enrichment, and so forth, not just better jobs. But certainly jobs are an important part of it.

The issue, then, is to figure out the political program that will most efficaciously allow us to dismantle barriers to freedom of movement. The idea of a guest worker program is to carve out a specific category of migration—short- and medium-term migrant workers—and focus on dismantling barriers to their freedom of movement. The idea seems to be that there will be less resistance to allowing X people come to the United States as temporary workers than there will be to allow X people to come to the United States as permanent residents. (And let’s be clear: there’s nothing about holding a green card that prevents an immigrant from going back to his native country, so X permanent green cards is intrinsically better, from a pro-liberty perspective, than X guest-worker cards.)

I just don’t think this political calculation makes sense. As we saw earlier this year, guest worker programs aren’t that popular, politically speaking. Will suggests that “Once the program is established and has demonstrated its efficacy, it will be possible to make a persuasive case for further North American labor-market integration, pushing toward a common North American labor market.” But it seems more likely to me that the opposite is true: any guest worker program that’s likely to actually be enacted will be numerically capped at a level that’s inadequate relative to the demand for immigrant labor. And so it will fail to significantly reduce illegal immigration because there will be a waiting list for guest worker permits just like there’s a waiting list for green cards. And then anti-immigration folks will point to it as an example of how immigration liberalization doesn’t work, and the real solution is build an even bigger wall and spend even more money harassing employers who employ hispanic workers.

My favorite analogy for the illegal immigration problem is to the story of labor market changes in Europe in the 17th and 18th centuries in de Soto’s Mystery of Capital. When Europe began to urbanize, tons of low-skilled immigrants flooded into the cities looking for work. The guilds successfully lobbied the government to restrict entry into their professions, and to undertake various measures, some of them quite brutal, to enforce those restrictions. The migrant workers reacted by setting up shantytowns in the suburbs of major cities, where they carried on their business in open defiance of the law. Despite repeated raids, the extralegal suburban economies continued to grow, to the point where Adam Smith once remarked:

If you would have your work tolerably executed, it must be done in the suburbs where the workmen, having no exclusive privilege, have nothing but their character to depend on, and you must then smuggle it into the town as well as you can.

European governments tried for decades to stop the growth of extralegal commerce, but as de Soto puts it:

European governments were gradually forced to retreat in the face of growing extralegality—as governments in developing and former communist countries are doing today. In Sweden, unable to stop the establishment of extralegal settlements, King Gustavus Adolphus had to visit each settlement and give it his blessing to maintain the appearance of government control. In England, the state was forced to recognize the new industries that were developing primarily in places where there were no guilds or legal restrictions; indeed, extralegals had created their own suburbs and towns specifically to avoid control by the state and the guilds.

I suspect that part of the reason for the governments’ capitulation was that they not only realized that the battle was hopeless in practical terms, but that the government’s war on unlicensed industry came to be seen as morally illegitimate. As the suburban industries grew and prospered, it became more and more obvious that there was no justification for shutting them down. Once people like Adam Smith began to see shopping in the suburbs as a reasonable and moral way to get better products at lower prices, it was only a matter of time before the governments of Europe would recognize reality and legalize extralegal businesses.

By the same token, I don’t think a more rational immigration policy will come about because of smart technocratic changes to immigration laws that brings immigrants into voluntary compliance with the law. Rather, I think we’ll see people continue to ignore the law when it’s unreasonable, and at some point the law will become so universally ignored that there will be no choice but to change it. I think a guest worker program might actually retard this process by reinforcing the perception that the state can and should decide how many people should be allowed into the country. And I’m especially uncomfortable with the sort of compromise we saw earlier this year, in which the anti-immigrant folks were asked to accept the guest worker program in exchange for beefed-up enforcement. I’m not sure how beneficial the guest worker program would be, but I’m sure a border fence and a federal government having power to decide when I’m allowed to work are bad ideas.