Cross-Border Migrations

The human species has a long nomadic history. The more recent concept of “cross-border migration” emerged from the formation of powerful territorially-based states in Europe. It gained practical importance after developments in transportation, communication, and industrialization enabled Europeans to colonize large parts of the rest of the world, and to relocate both within Europe and overseas in large numbers. By the early 20th century, with the general adoption of passports and border controls, cross-border migration had become a widespread political concern, and foreign workers a major source of labor used by businesses large and small.

In 2007 about 200 million people, or 3 percent of the world's population, lived outside the country of their birth. Likewise, the roughly 100 million migrant workers globally amounted to about 3 percent of the world's workforce. In certain regions, especially Western Europe and North America, and in certain occupations, such as computer programming, nursing, restaurants, and crop harvesting, these percentages have been much higher. International migrant remittances to developing countries totaled about $250 billion in 2005.

Most modern cross-border migration is associated with economic differences between countries. In 1975 per capita gross domestic product was about 40 times greater in high-income countries than in low-income countries; by 2000 this ratio had risen to over 60. Other “pushes” and “pulls” motivating international migration are noneconomic, notably family reunification and mass flight from disaster. Refugees with a “well-founded fear of persecution” have protected status under international conventions and within many national jurisdictions. In practice, however, [Page 439]“economic migrants” and “political refugees” are overlapping categories. Similarly, although a cross-border migrant is generally one who moves internationally and stays at least a year in the new “host” country, it is often difficult to distinguish between “temporary” and “permanent” migrants. A more recent concern is the potential for cross-border refugee flows provoked by natural disasters, particularly catastrophic floods and droughts associated with global climate change.

A densely populated Mexican city, at right, juts up against the heavily fortified border with the United States. In 2000 per capita gross domestic product was over 60 times greater in high-income countries than in low-income countries.

A considerable fraction of cross-border migration moves without documentation and illegally into receiving countries. This causes practical problems along migratory routes and political problems for governments of sending countries (whose people want to leave) and of receiving countries (which cannot “control” their borders). Undocumented migrants also face the risk of exploitation by smugglers and difficulties of social integration while working “underground.” How to deal with illegal immigration has recently been a major political issue in the United States.

Government Policies

Government policies on cross-border migration have been inconsistent. There are far fewer border restrictions on leaving than on entering. Official policies also partly reflect popular ambivalence. Voters in receiving countries are often apprehensive about large numbers of foreigners in their midst, but not opposed to readily available low-cost labor. Migrant workers are usually more productive than they would be at home, but the resulting net benefits of cross-border migration are unevenly distributed. At times, low-skilled workers in richer countries may suffer wage declines due to migration. Movements of migrants, however, are significantly influenced by economic cycles, not just by public policies or popular attitudes.

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