[1] The exact numbers are debated, but Mark Wyman concludes: "The totals are so enormous: at least one-third of the 52 million Europeans who left Europe between 1824 and 1924 returned permanently to their homelands.
[3] It should also be distinguished from circular migration, in which migrants repeatedly travel between origin and destination countries, for example to plant and harvest crops each season.
Migrants may face challenges in reintegrating into their home societies, including finding suitable employment, adapting to changes in the local environment, or dealing with the stigma associated with migration.
Involuntary or forced repatriation is the return of refugees, prisoners of war, or civil detainees to their country of origin under circumstances that leave no other viable alternatives.
[21] According to modern international law, prisoners of war, civil detainees, or refugees refusing repatriation, particularly if motivated by fears of political persecution in their own country, should be protected from refoulement and given, if possible, temporary or permanent asylum.