As a believer in free markets I believe that free exchange of one's labor and being able to travel unhindered will, in a free market, promote wealth. In our society there is enough subsidization that this is not the case. In a free market you have the motivation of wealth (or at least survival) to be productive; In the United States survival is rarely a motivation we encounter (I imagine the obsession with apocalypse scenarios is spawned from our innate desire to need to survive). Wealth, too, is becoming less of a motivation for productivity.
In this sort of society, those who are productive are drained to support those who are not productive. The end result is a decline in productivity and thereby a decrease in wealth.
I support freedom of travel, though. It will likely accelerate a descent into economic decay but that's OK because it was bound to happen anyway.