How Many Illegal Aliens are in the US?
By Spencer Raley | October 23, 2017 | View The Full Report (PDF)
As of 2017, FAIR estimates the number of illegal aliens in the US to be approximately 12.5 million. This number is slightly higher than FAIR’s previous estimate of 12 million in 2011.
Estimating the size and characteristics of the illegal alien population is an inexact science. Anyone claiming to have calculated a definitive number should be looked upon skeptically. There is no central database of illegal aliens. Furthermore, the Department of Homeland Security only counts those who enter and leave in a lawful manner. Those who evade immigration authorities or sneak across the border are not counted.
Most available sources used for estimating the total number of illegal aliens rely on migrants to self-report whether or not they hold lawful status. Illegal aliens have a strong motive to lie when asked about their immigration status. Many, understandably, feel that disclosing their unlawful status will make them vulnerable to immigration officials. Therefore, the accuracy of these statistics is doubtful, at best. Data collected by the Census Bureau, for example, attempts to differentiate between citizens, illegal aliens and lawfully present immigrants. However, this information is, again, self-reported by survey respondents without an independent verification process. The Census Bureau does not require or ask for any kind of documentation to verify that their respondents are answering demographic questions honestly.
https://www.fairus.org/issue/illegal-immigration/how-many-illegal-immigrants-are-in-us