Capitalism and Immigration

Bryan Caplan imagines a dialogue between a wealthy man and radicals who have kidnapped him. The wealthy man convincingly justifies his position and the means by which he obtained it. Toward the end, we get this:

Jan: Now you're changing the subject. Why don't you give away your riches to the poor?

Hardenberg: Simple. Because they're strangers and I don't owe them anything. It may not be their fault that they're poor, but it's certainly not mine. And unless you quit being a bum, get the highest-paying job you can, and hand over all your earnings above your basic needs to the poor, you're going to have to give same answer.

Which reminds me of nothing so much as Dr. Caplan's position on immigration, viz. that the world's poor would be better off if they immigrated here, and that we have the duty to take their plight into consideration. My reply to that is exactly what the rich man says: why is it my problem? "They're strangers and I don't owe them anything. It may not be their fault that they're poor, but it's certainly not mine."

In contrast, the Americans who are being displaced - from jobs and neighborhoods both - are my fellow citizens. While that may not define or delimit my obligations to them, surely it's something. That's a far greater connection than I have with a Guatemalan or Khazak. But in the world of libertarian economics, people are all just replaceable units, with no connection to an historic culture, no differences in ability or loyalty or capacity for citizenship, no differences in religion or IQ.