What are the main factors underlying international migration? Are the flows determined by very different patterns of population growth in the North and the South, or by economic and social disparities? According to Douglas S. Massey, migration flows are directly related to globalization and to the increased flows of capital, goods and services.
As proof, he takes the case of the United States, where there have been two periods of very high immigration: first from 1800 to 1914, when immigration was directly correlated with the growth of foreign trade; and then since World War II and above all the fall of the Berlin Wall, with the rise of globalization, again clearly linked to the strong growth in foreign trade.
The difference between these two periods is that at the beginning of the 20th century, immigration was quite acceptable to the receiving country, whereas now the US tries to control it -albeit without much success. Another difference is that in the first period of globalization, the immigrants came from Europe, whereas now they come from America's main trading partners: Mexico, the Philippines, China...
In conclusion, Massey stresses that the growth of international migration cannot be halted and is directly linked to the phenomenon of global trade. He also argues that the immigrants in future will come not from the poorest and most populous countries but from countries with the highest levels of international trade.