Yale Researchers Debunk the Myth of 11 Million Illegal Immigrants

• Edwin S. Rubenstein
• April 13, 2021
• Forum Papers
• Forum Paper
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Yale Researchers Debunk the Myth of 11 Million Illegal Immigrants
An NPG Forum Paper
by Edwin S. Rubenstein
 April 2021

Call any journalist, lobbyist, activist, or reasonably well-informed citizen – in red state or blue – and ask: a. How many illegal immigrants live in the U.S.?, and b. What is the source of your number? Almost without exception he or she will answer a. 11 million, and b. The Pew Research Center.

Never has so much of the nation’s well-being depended on the accuracy of that 11 million estimate. The proposed “path to citizenship” for undocumented residents has been called “the boldest immigration agenda any administration has put forth in generations.”1 The pro amnesty crowd says it will lift millions of illegal immigrants who were in the U.S. before January 1st “out of the shadows” into higher paying jobs. Those against it warn that native-born workers will be displaced by the newly amnestied, while even more illegals will be induced to enter the country.

Like a tornado that won’t quit, arguments have spun around and around these issues for years. At the eye of the storm lies a fairly stable and unquestioned number: 11 million illegal aliens.

But, a paper by three Yale-affiliated researchers suggests all the perceptions and arguments based on that figure have a faulty foundation; the actual population of undocumented immigrants residing in the country is much larger, perhaps twice as high, and has been underestimated for decades.

Applying their mathematical models to a range of demographic and immigration data, Yale researchers estimated that 22.1 million illegal immigrants resided in the U.S. in 2016. (top line) Even when they deliberately low-balled their estimate – by using parameters designed to produce an extremely conservative number, they came up with 16.7 million undocumented immigrants (middle line), which is 50% above Pew Research’s 11.2 million figure for that year. (bottom line) Pew’s is the most frequently cited figure among the DC-based think tanks specializing in immigration issues.

The results, published in a peer reviewed academic journal, surprised the authors themselves. They started with a conservative model, and expected results to be well below the 11 million consensus. “Our original idea was just to do a sanity check on the existing number,” co-author Edward Kaplan, a professor of Operations Research at the Yale School of Management, said, adding that “Instead of a number which was smaller, we got a number that was 50% higher. That caused us to scratch our heads.”

While 11 million is the number “that everybody quotes…when you actually dig down and say, ‘What is it based on?’ You find it’s based on one very specific survey and possibly an approach that has some difficulties. So we went in and just took a very different approach,” observed economist Jonathan Feinstein, another co-author.

The “specific survey” Feinstein refers to is the annual American Community Survey (ACS). We checked out the ACS website. In 2016, it reported 43.7 million immigrants were living in the U.S., of whom 51.4% – or 22.5 million – were not citizens.4 Not all non-citizens are illegal aliens, of course. Many entered legally, but haven’t been in the country long enough to qualify for a Green Card – and the path to citizenship entailed by that document… Continue reading the full Forum paper by clicking here.