Another reason why the oriundi practice was not considered overly controversial in the first half of the 20th century is to do with patterns of emigration.
Latvia's class and ethno-linguistic background has a strong influence over the patterning of emigration.
Observed patterns of emigration from Moldova and Georgia between 1991 and 2010 provide evidence of a progressive feminisation of migration.
Patterns of emigration have ebbed and flowed over the years but more than 400,000 Irish citizens call London home and there are large, vibrant Irish communities in most of England and Scotland's largest cities.
While African migration remains overwhelmingly intra-continental, since the late 1980s there has been an acceleration and spatial diversification (beyond colonial patterns) of emigration out of Africa to Europe, North America, the Gulf and Asia.
The pattern of Spanish emigration changed after World War II.
Even the country's longstanding pattern of mass emigration was reversed, with the boom attracting a growing number of incomers and creating a new multiculturalism.
Significant differences were observed for effects of patch size, dispersal distance, NPP conditions and all two- and three-way interactions on patterns of net emigration.
What has not happened is a pattern of working-class emigration out of America, as one sees out of Mexico or Ghana or Cambodia.
But May's hopes of achieving the target are also jeopardised by the second part of the net migration equation – the recent pattern in emigration which is now at its lowest level since 2001.
During that period the nature of emigration patterns changed, becoming less stable.
