You may have heard by now that measles is enjoying a renaissance in the Western US. You may have even heard that the disease has shown up on our fair shores thanks to a combination of domestic anti-vaccination sentiment and contaminated foreigners.
If you click through on the link, the CDC findings support these claims. Though, if you listen to the talk radio or Web chatter, you might be forgiven for substituting "obtuse California homeopathy wiggins" for "anti-vaccination" and "border-jumping Mexican" for "diseased foreigner." But the bulk of last year's outbreak occurred among the Amish and the original vector was from the Philippines.
It would be tedious of me to add my voice to the chorus singing "get your kids vaccinated," particularly if the groups that are at the most severe risk (the Amish, eg) are the least likely to heed my sanctimonious advice. So I'll focus my attention on the source of outbreaks: foreigners.
If there must be a government, surely among its core functions is to provide basic public goods. Strict immigration quotas make it next to impossible for otherwise law-abiding, peaceful foreigners to make a new life in the US. So they cross the border dangerously, in the dead of night, often with the assistance of unaccountable misfits. And occasionally, it seems, bearing infectious disease.
Consider an alternative scenario. Lift the quota system entirely. Divert human resources towards controlled points of entry, where migrants can be screened for criminal backgrounds and health. Anyone still attempting to surreptitiously cross the border will have self-identified as a rogue. As it is now, the wheat and the chaff do not self-separate, meaning that every interdiction agent out there is wasting time processing people whose only crime is to violate legislated, arbitrary quotas. Relieve them of this burden so that they can work on catching actual dangerous people. And consider that it's probably more cost-effective to inoculate previously unvaccinated migrants right there on the border than to treat scores of American citizens after an outbreak has already erupted.
Even assuming "keep 'em all out with a big wall and machine guns" is a valid moral position to adopt, it might be that the costs of this policy are prohibitively high and the unintended consequences too grave to accept. Ending immigration quotas could well help curb threats to public health and safety.
Sounds pretty euvoluntary to me.