Robert Shapiro surveys the literature:
The New Policy Institute (NPI) asked me to review all of the available data and economic studies of recent U.S. immigration. With my colleague Jiwon Vellucci, we found, to start, that more than one-third of recent immigrants come from Europe and Asia, while less than 57 percent have come from Mexico and other Latin American nations. The popular portrait of recent immigrants is off-point in other respects as well. While more immigrants than native-born Americans lack high school diplomas, equivalent shares of both groups have college or post-college degrees. That finding should make it unsurprising that 28 percent of U.S. immigrants work as managers or professionals, including 38 percent of those who have become naturalized citizens or the same share as native-born Americans.
Many Americans would probably acknowledge that their concerns about immigration lie principally with those who are undocumented. No one likes being reminded that the world’s most powerful nation hasn’t figured out how to effectively police its own borders. But the data also show that these undocumented people, who account for 30 percent of all recent immigrants, embody some traditional values much more than native-born Americans. For example, while undocumented male immigrants are generally low-skilled, they also have the country’s highest labor participation rate: Among working-age men, 94 percent of undocumented immigrants work or actively are seeking work, compared to 83 percent of the native born. One critical reason is that undocumented immigrants are more likely to support traditional families with children: 47 percent of undocumented immigrants today are part of couples with children, compared to just 21 percent of native-born Americans.
The evidence regarding the impact of immigration on wages also turns up some surprising results. First, there’s simply no evidence that the recent waves of immigration have slowed the wage progress of average, native-born American workers. Overall, in fact, the studies show that immigration has increased the average wage of Americans modestly in the short-run, and by more over the long-term as capital investment rises to take account of the larger number of workers. Behind those results, however, lie winners and losers – although in both cases, the effects are modest. Among workers, the winners are generally higher-skilled Americans: For example, when a factory or hotel hires more low-skilled workers, demand also increases for the higher-skilled people who manage those workers or carry out other professional tasks for an enterprise that’s grown larger.