Two Yale profs, Edward Kaplan and Jonathan Feinstein, have published a study that suggests that the number of immigrants in the United States illegally may be double the official estimates. From Yale Insights:
Using mathematical modeling on a range of demographic and immigration operations data, the researchers estimate there are 22.1 million undocumented immigrants in the United States. Even using parameters intentionally aimed at producing an extremely conservative estimate, they found a population of 16.7 million undocumented immigrants.
The results, published in PLOS ONE, surprised the authors themselves. They started with the extremely conservative model and expected the results to be well below 11.3 million.
“Our original idea was just to do a sanity check on the existing number,” says Edward Kaplan, the William N. and Marie A. Beach Professor of Operations Research at the Yale School of Management. “Instead of a number which was smaller, we got a number that was 50% higher. That caused us to scratch our heads.”
The eye-catching graphic from the article is reproduced above. What it illustrates is that the number of people here illegally is something between 16 million and 35 million and the official estimate of 11 million is not only wrong but very wrong.
The authors of the study’s conclusion is exactly the right one: to make policy you need to know the scale of whatever you’re dealing with.
This study doesn’t just have implications for immigration policy. It affects policy across a wide range of issues—immigration, health care, housing, transportation, and infrastructure. Our policies need to be designed for the world as it is not the world of our hopes or our fears.
We should start measuring a variety of indirect sources—highway and public transport utilization, water and sewer use, and the like. Clearly, we need better estimates.