Given the frequency with which the subject comes up in the presidential race and the urgency with which Republican nominee Donald Trump promises to halt it, the casual observer would assume that illegal immigration is a huge and growing problem in the United States. But researchers looking at data from the Department of Homeland Security believe that the number of people entering the country illegally has fallen to historically low levels in recent years.
Measurement is difficult because, obviously, people entering the country illegally don’t stop and identify themselves on the way over the border. However, looking at DHS data on the arrest rate of illegal entrants at the Mexican border, Federico S. Mandelman, a research economist and associate policy adviser at the Federal Reserve Bank of Atlanta, and Andrei Zlate, a senior financial economist in the Boston Fed's Risk and Policy Analysis Unit, found the numbers have been plummeting.
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“The apprehensions series displays spikes that coincide with well-known episodes of increased illegal immigration into the United States, such as after the financial crisis in Mexico in 1995 or during the U.S. housing boom in the early 2000s,” they write. “Importantly, the series also shows a sharp decline in the flows of illegal immigration at the U.S.-Mexico border during the last recession, and those flows have remained at historically low levels since then.”
The authors note also that the decline in arrests coincides with a “remarkable increase” in the intensity of Border Patrol activity, measured by the number of personnel assigned to the U.S.-Mexico border region.
Looking at demographic and economic data, Mandelman and Zlate say that there may be good reason to believe that the sort of mass movement from Mexico to the U.S. that was seen in the years leading up to the Great Recession could be a thing of the past.
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“Mexico's fertility rate has fallen (as in some Central American economies), and economic growth there has mostly outpaced that of the United States,” they write. “Therefore, it is perhaps not too surprising that demographic trends—along with greater enforcement—have caused the inflows of undocumented migration at the U.S.-Mexico border to slow in recent years. Shifts in demographic and economic factors across countries are likely to continue to influence undocumented immigration in the United States.”
To be sure, the country still has more than 11 million undocumented immigrants within its borders, as Trump never tires of pointing out. But the impression that he and many others give, of waves of Mexicans crossing the border to steal U.S. jobs, appears to be misleading at best and at worst, completely false.