Are you saying a poor American can go work at Burger King in Sweden? That's revelatory.
This is the best document I could find: https://portal.research.lu.se/portal/files/40268826/Labor_Mi...
Edit: "Authority on this" as in Migrationsverket is the entity that receives the application and ultimately decides to grant/deny it.
[0] - https://www.migrationsverket.se/English/Private-individuals/...