The Catholic migration is attributed to an expectation of persecution of Catholics by the North Vietnamese government, as well as publicity employed by the Saigon government of the President Ngo Dinh Diem.
Den katolske migration skyldes en forventning om forfølgelse af katolikker af den nordvietnanske regering samt en kundgørelse fremsat af præsident Ngo Dinh Diems Saigon-regering.