A combination of cheap transportation and enormous disparities in income across countries has inspired unprecedented numbers of people to uproot: there are now 230 million people around the world living outside the country of their birth, 46 million of them in the United States. Not surprisingly, immigration tends to flow from poor places to rich ones: in the world’s 18 richest countries, immigrants constitute 16 percent of the population. If one includes those who are descendants of recent immigrants, that percentage is significantly larger and is certain to grow, since immigrants generally have more children than domestic populations. Consider that, in 2010, 13 percent of the U.S. population was born outside the country, yet 24 percent of those younger than 18 had foreign-born parents.
Policymakers in rich countries have tended to treat immigration as a challenge, but a surmountable one. Previous eras of mass migration produced good outcomes, for immigrants and settlement countries alike. The vast pool of immigrants that arrived in the United States prior to 1914 -- a group that included Christian Arabs, Greeks, Hungarians, Italians, Japanese, Jews from the Russian Empire, and Scandinavians -- assimilated rapidly and contributed to an economic boom. Similarly, since World War II, Australia, Canada, and New Zealand have successfully absorbed large numbers of immigrants from varied countries and backgrounds.
But it would be a mistake to assume that those experiences will be repeated for all immigrants. There is reason to believe that many recent migrants to both the United States and Europe will have a much more difficult time than their predecessors. Meanwhile, the countries in which they settle are less likely to see the benefits of immigration as they experience heightened social tensions and widening social inequality. Policymakers would be wise to take those risks into account. Rather than focus on policies for integrating new immigrants, they should concentrate on avoiding selection policies that threaten to create near–permanent ethnic or religious underclasses.
HOW ASSIMILATION WORKS
The successful assimilation of earlier immigrants is often misunderstood. It’s true that