Spencer Raley at the Federation for American Immigration Reform (FAIR) recently wrote a criticism of a recent Cato brief that estimates illegal immigrant incarceration rates in the United States. Much of Raley’s critique is perplexing as following his methodology advice would not only lead to an erroneous result but it would reduce illegal immigrant incarceration rates – which is the opposite result that he and his organization desire. Raley’s points are quoted below, my responses follow.

The authors rely on faulty, voluntary data from the Census Bureau’s American Community Survey (ACS). Even mainstream organizations like Pew Research acknowledge that many illegal aliens are slow to volunteer information about themselves to the federal government. That’s why reputable research organizations assume a certain undercount when relying on ACS data. Hesitation to self-report personal information is only increased when surveys include questions about criminal history. So, from the start, the primary source used in this study will yield an undercount of incarcerated illegal aliens because it relies on self-reported data.

The responses of prisoners are recorded by Census officials who interview a sample under the supervision of prison officials who also supply information like immigration status and country of birth. Although it’s easy for people outside of prison to avoid a Census official, it’s quite difficult for a prisoner to do so if he or she has been selected for an interview by the ACS. Since the ACS doesn’t ask about the respondent’s criminal histories, Raley’s criticism here is perplexing. If anything, using the ACS would yield an undercount of the illegal immigrant population – which would increase the illegal immigrant incarceration rate in our brief. 

They also misstate illegal alien crime data from Texas. The authors sliced and diced data from Texas’ Department of Public Safety, claiming that the original data offered by the state was far too high, and that illegal aliens in Texas are half as likely to be incarcerated as U.S. citizens. The real numbers, however, tell a different story. Based on data compiled between June 2011 and February 2019, 25,000 illegal aliens are booked into Texas state and local jails annually, on average.

Raley makes several errors in summarizing my Texas crime research. First, I didn’t “slice and dice” any data from Texas. I took the numbers released by the Texas Department of Public Safety, divided them by the relevant subpopulation of Texas in 2015, and then multiplied the result by 100,000 to get a criminal conviction rate. Second, I didn’t compare illegal immigrants to U.S. citizens. I compared illegal immigrants to native-born Americans and legal immigrants separately. Third, my Texas study did not analyze incarceration rates. My Texas study looked at criminal conviction rates. Incarceration rates and criminal conviction rates are different.

Raley’s other criticisms are answered by reading the methodology section of our brief. This is the most relevant section here which explains why we looked at the 18–54 population:

Another limitation of the ACS data is that not all inmates in group quarters are in correctional facilities. Although most inmates in the public-use microdata version of the ACS are in correctional facilities, the data also include those in mental health and elderly care institutions, as well as those in institutions for people with disabilities. These inclusions add ambiguity to our findings about the illegal immigrant population but not about the immigrant population as a whole, because the ACS releases macrodemographic snapshots of inmates in correctional facilities, which allows us to check our work.


The ambiguity in illegal immigrant incarceration rates mentioned above prompted us to narrow the age range to those who are ages 18–54. This age range excludes most inmates in mental health and retirement facilities. Few prisoners are under age 18, many in mental health facilities are juveniles, and many of those over age 54 are in elderly care institutions. Additionally, few illegal immigrants are elderly, whereas those in elderly care institutions are typically over age 54. As a result, narrowing the age range does not exclude many individuals from our analysis. We are more confident that our methods do not cut out many prisoners because winnowing the 18–54 age range reduces their numbers to about 4.5 percent above that of the ACS snapshot. Natives in our results include both those born in the United States and those born abroad to American parents.