This situation isn't the same thing as the environmental pollution one you provide above. The pollution example involves damaging the physical property of others by failing to contain one's own dangerous property (the toxic waste).
Your example about "unemployable young men" actually scares me because of its hidden liberal implications--it basically says that people are entitled to jobs (other people's money), and there's a hidden threat in there in which the unemployed will engage in some sort of revolution to take by force what they're not being voluntarily provided.
It's the same argument that I've seen liberals use to defend welfare programs (especially FDR's programs, historically). They say that if the government hadn't provided welfare payments, the "desperate" would have begun committing crimes. [See how close this runs to the liberal "poverty causes crime" argument?] It seems like a veiled threat against property to me, akin to Mafia "protection money." All I can say is that the answer isn't to bribe people to obey the law and respect private property. The answer, in such situations, is the police and National Guard.
For these reasons, perhaps there's a better way you could defend Federal forced integration laws than on economic grounds?
Yes, when they were deprived access to the voting booth, to civil courts, and the legal ability to engage in trade with the white majority, they would have been fully justified in resorting to violence. It would have been quite ugly, and something from which the nation never would have recovered - all so a bunch of white trash could feel superior to blacks.
Does that help?