Controlled migration for the foreseeable future. Maybe if the entire world reaches a broadly similar level of human development, including comparable levels of

Controlled migration for the foreseeable future. Maybe if the entire world reaches a broadly similar level of human development, including comparable levels of infrastructure and social support, migration can be opened up quite a bit. But right now it would simply mean that developed nations would see a flood of people immigrating just to get those great services, and it would crush their system. So we need controls to keep the change manageable and ensure that the tax base scales appropriately to maintain the expected levels of service.