Wednesday, June 12, 2019
BY NOLAN RAPPAPORT, OPINION CONTRIBUTOR — 06/09/19 10:30 AM EDT
No one knows exactly how many undocumented aliens are in the United States, or from where they come. Most estimates range wildly, from 10 million to 22 million.
What we do know, from various studies and estimates, is that Central Americans illegally crossing the U.S.-Mexico border are not the only source of our problem.
Undocumented aliens come here from all over the world — and visa overstays are as great a problem as those illegal border crossings shown nightly on TV and debated endlessly in Congress.
The inherent difficulty in calculating the numbers is that undocumented aliens usually avoid drawing attention to their status, to avoid being deported.
In February 2018, the Center for Migration Studies estimated 10.8 million undocumented aliens living here in 2016. Last December, the Department of Homeland Security (DHS) estimated 12 million undocumented aliens as of January 2015. On June 3, Pew Research Center put the number 10.7 million in 2016.
None of these estimates seems reliable. They are based on Census Bureau data: The number of legal immigrants in the country was subtracted from the number of census participants who acknowledged they were not born in the U.S.
Yet, Census information is self-reported by survey participants with no independent verification. There’s no way of knowing if a significant percentage of the undocumented alien population participated. And it is utterly unrealistic to expect undocumented aliens to admit their status in surveys conducted by the federal government.
Professors from MIT and Yale, using more sophisticated methodology, estimated in September 2018 that 22.1 million undocumented aliens are in the U.S. Their estimate is based on operational data such as border apprehensions, deportations, visa overstays and demographic figures, as well as mortality and emigration rates. They evaluated the data with a mathematical model that estimates and tracks population inflows and outflows.
Yet, some of these factors are not wholly reliable. For instance, the professors acknowledged concern about the accuracy of apprehension data: "We don't know the number of people who cross the border successfully — we only know when people get caught trying."
The visa overstay numbers they used may not be accurate, either.
An “overstay” is a non-immigrant visitor who was admitted for a specified time but remained longer without permission. Most overstay data pertains to non-immigrant visitors who came here through the Visa Waiver Program, which allows eligible aliens from 38 countries to enter the United States as non-immigrant visitors without going through the visa process.
Although the Visa Waiver Program was established in 1986 and entries began in 1988, overstay records were not available until 2016. Moreover, entry and exit data is only collected at air- and seaports; it is not collected at land ports.
The DHS “Fiscal Year 2018 Entry/Exit Overstay Report” indicates 666,582 suspected overstay “events” in fiscal 2018. That includes 68,593 students or exchange visitors and other categories of non-immigrants who entered with visas.
The term “event” refers to the number of “expected departures,” not to the number of actual aliens who were expected to depart — and the Center for Immigration Studies claims this makes the overstay rates deceptively low.
To explain, using DHS methodology: If 10 non-immigrant visitors enter the U.S. three times each in a year, that would result in a total of 30 “expected departures.” If they all leave as required, but an additional visitor makes only one visit and overstays, the overstay rate would be 1 in 31 entries, or about 3 percent. Yet, if the overstay rate were calculated by counting people, the rate would be 1 in 11, or about 9 percent.
According to the Center for Migration Studies, the number of known overstays significantly exceeded illegal border crossings from 2010 to 2017.
For the full story with charts and figures, click here.