Undocumented immigrants Undocumented immigrant population roughly double current estimate

Published 25 September 2018

The number of undocumented immigrants in the United States is roughly twice as high as commonly believed, according to new research. The research found that the number of undocumented immigrants living in the country is about 22.1 million, nearly twice the most prominent current estimate of 11.3 million. Even using extremely conservative parameters, the study estimates a population of 16.7 million undocumented immigrants, nearly 50 percent higher than the widely-accepted population figure.

The number of undocumented immigrants in the United States is roughly twice as high as commonly believed, according to new research from MIT Sloan and Yale professors.

The research found that the number of undocumented immigrants living in the country is about 22.1 million, nearly twice the most prominent current estimate of 11.3 million. Even using extremely conservative parameters, the study estimates a population of 16.7 million undocumented immigrants, nearly 50 percent higher than the widely-accepted population figure. The study, published in PLOS ONE, was conducted by MIT Sloan’s Mohammad Fazel-Zarandi, a senior lecturer in the operations research and statistics group, and his colleagues, Edward Kaplan and Jonathan Feinstein, both from Yale School of Management.

“Immigration policy is a hot-button issue in the U.S. and the question of how to address undocumented immigrants provokes passion on both sides,” Fazel-Zarandi said. “Debates about the amount of resources to devote to undocumented immigrants and the relative benefits and disadvantages of various policies — including deportation, amnesty, and border control — depend on having a correct estimate of just how many of them are living here. The number sets the scale.”

The commonly quoted estimate of 11.3 million is extrapolated from population surveys. “We read that [the previous estimates] were based on surveys, but surveys may not be the most appropriate method for measuring hidden populations,” Fazel-Zarandi said. In the case of undocumented immigration, it’s particularly challenging, he said, since undocumented immigrants might have an incentive to stay undetected.

“It’s likely that undocumented immigrants are more difficult to locate and survey than other foreign-born residents and if contacted, they may be inclined to misreport their country of origin, citizenship, and number of household residents, fearing the legal consequences of revealing their status,” he said.