Although open labor migration would bring massive economic benefits, it inspires fear among source and destination countries alike. A "reversible-bond" system would insure both sides against the risks and allow labor markets’ actual needs to dictate migration flows – thus unlocking the global economy's true potential.
https://prosyn.org/cLsYMNT
NEW YORK – Almost immediately after the suspects in the Boston Marathon bombings were revealed to be immigrants, opponents of immigration reform in the United States seized on the case to highlight the danger of adopting a more open approach to the issue. After all, stoking public fears effectively derailed immigration reform in the wake of the terrorist attacks of September 11, 2001; why shouldn’t it work today, as the US Congress takes up the issue again?