The last thirty years have witnessed some unusual cases of migration. Displaced persons, frequently changing their destinations several times over the period from 1945 to 1960, swelled the number of international migrants.
In the first fifteen years after World War II, some 3.5 million migrants came to the United States under special legislation that allowed the bypassing of immigration quotas.
Israel was virtually repopulated as thousands of Palestinian Arabs were displaced and Jews (mainly from Europe) replaced them.
Canada has welcomed over 2 million migrants since 1950, while Australia, Brazil, France, and Argentina have each received over a million. Even Britain experienced in-migration during this period, although it was more than balanced by emigration. The composition of the British population was much changed as a result.
Renewed economic vigor in Europe and a general tightening of world controls have reduced emigration from that continent since 1960. Out-migration from Soviet bloc countries and China is tightly controlled.
No new economic bonanzas, with the exception of the Arab oil-producing countries, have appeared on the horizon in recent years. The greatest numbers involved in international movement now are attributed to political unrest.
Each recipient country temporarily makes mass movement possible for chosen groups (for a limited time period) following major upheavals. For example, over 500,000 Hungarians migrated to the United States and Canada following the 1956 revolution.
The evacuation of Vietnamese to the United States and the increased migration of Soviet Jews to Israel and the United States (following political protests) are other cases in point.
New trends are appearing. With legal routes effectively closed, large numbers of Latin Americans have entered the United States illegally (some 4 to 6 million since 1960).
New groups, such as (Hindu) Indians, Pakistanis, Middle Eastern peoples, and West Indians have begun to appear in the United States in significant numbers.
Physicians, engineers, technical personnel, and college professors have prominent representation among these groups. In effect, developed area migration policies are acting as a “brain drain” on the sending countries.
Brain drain is a highly selective migration, motivated by personal ambition for a superior standard of living.
An interesting double brain drain is operated in Great Britain among medical doctors. British physicians migrated to the United States, Australia, and Canada where they could greatly increase incomes.
They were replaced in British hospitals and clinics by Indian and Pakistani doctors, who in turn upgraded their incomes through migration.