Properly interpreted, the DPS data suggests that illegal immigrants in Texas are more likely to be convicted of murder and sexual assault than the national average.
So write Sean Kennedy, Jason Richwine, and Steven A. Camarota, “Misuse of Texas Data Understates Illegal Immigrant Criminality,” Center for Immigration Studies (CIS), Oct. 2022. DPS is the Texas Department of Public Safety.
Her brief report is a critique of previous work that found lower serious crime rates among illegal immigrants in Texas. One of the studies they criticize comes from Alex Nowrasteh of the Cato Institute. (Disclosure: I donate a small amount of money annually to Cato, which got me started as a political analyst in 1979, and I consider Alex Nowrasteh a friend.)
Nowrasteh has responded that the three authors made two errors in calculating the homicide rate for illegal aliens. According to Nowrasteh, they overestimated the numerator and underestimated the denominator. Nowrasteh discusses both in detail. I don’t know enough to judge his analysis of the raw homicide counts, but he makes a strong argument that they underestimated the denominator, that is, the number of illegal immigrants in Texas.
The CIS Crime Report uses the second lowest available estimate of Texas’ illegal immigrant population, provided by the Center for Migration Studies (CMS), which also produces the lowest statewide estimate. A lower illegal immigrant population automatically leads to a higher illegal immigrant crime rate by reducing the denominator (assuming the numerator stays the same or increases). Curiously, CIS did not use their own estimates of the illegal immigrant population they produced elsewhere, choosing instead to rely on the far lower CMS population estimates. What’s even stranger about CIS’s decision to ignore its own population-only research on the number of illegal immigrants in its crime report is that both pieces of research were co-authored by Steven Camarota.
The CIS’s own examination of the size of the illegal immigrant population in its Population Only Research paper estimates a statewide illegal immigrant population of 11,390,000 in 2018 and 11,480,000 in 2019, compared to CMS’ estimate of 10,565,000 in 2018 and 10,348 .884 in 2019 — a difference from 825,000 in 2018 and over 1.1 million in 2019. In other words, in its paper focusing on estimates of the illegal immigrant population, the CIS estimates a nationwide illegal immigrant population that increased by eight in 2018 percent and 2019 was 10.9 percent higher than the CMS. However, the CIS authors took advantage of CMS’s lower illegal immigrant numbers for its paper on illegal immigrant crime in Texas. CIS’s pure population estimates imply an illegal immigrant population in Texas of 1,940,000 (which DHS found using the same methods), but CMS found 1,781,752. CIS therefore used a population estimate for the number of illegal immigrants in Texas that is 7.5 percent lower than their pure population estimates in 2018 and 8.9 percent lower in 2019.
Later he writes:
In their pure population research, CIS boasted that their estimates of the illegal immigrant population matched DHS’s own population estimates. The CIS-only population research did not break down their estimates by state, but the DHS did. Since the DHS and CIS methods are almost identical (they use different data sources), I can use the DHS’s Texas-level estimates in the example below. The slightly higher numbers of illegal immigrant crime in the CIS, coupled with pure CIS population research implying an illegal immigrant population in Texas of 1,940,000 in 2018, shows that illegal immigrant homicide rates are high under what Cato’s methods of estimating the illegal immigrant population would have been if compared to CIS crime data (Figure 1). CIS’s pure population research, combined with their data on illegal immigrant homicides, gives a homicide rate of 2.9 per 100,000 illegal immigrants, compared to Cato’s three per 100,000. Both rates are lower than Cato’s homicide rate in Texas in 2018.
DHS is the Department of Homeland Security.
You may be wondering why the focus is on Texas. The main reason is that their data is more finely divided.
See this October 2020 paper co-authored by Alex Nowrasteh for a previous comparison of different serious crime rates.