Whether illegal immigrants bring a significant amount of crime to the United States is one of the most important questions to answer in the debate over immigration policy. President Trump also seems to think so as he launched his campaign in 2015 with the now infamous quote: “[Mexican illegal immigrants] are bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people.” From executive orders to major talking points to the President’s speeches, which Vox reporter Dara Lind has aptly described as “immigrants are coming over the border to kill you,” Trump is interested in this important topic.
It is difficult to know whether illegal immigrants are more likely to commit crimes than native-born Americans are. All immigrants have a lower criminal incarceration rate and there are lower crime rates in the neighborhoods where they live, according to the near-unanimous findings of the peer-reviewed evidence. Since 1911, large nationwide federal immigration commissions have asked whether immigrants are more crime-prone than native-born Americans and each one of them answered no, even when the rest of their reports unjustifiably blamed immigrants for virtually every problem in the United States. From the 1911 Immigration Commission, also known as the Dillingham Commission, to the 1931 Wickersham Commission, and 1994’s Barbara Jordan Commission, each has reported that immigrants are less likely to commit crimes than native-born Americans.
That research combines legal and illegal immigrants to calculate a crime rate for all immigrants, but the modern debate is over the crime rates of illegal immigrants. Most people seem to accept that legal immigrants have lower crime rates than natives. Measuring illegal immigrant crime rates is challenging for several reasons. First, the American Community Survey does not ask which inmates in adult correctional facilities are illegal immigrants. Second, federal data on the number of illegal immigrants incarcerated on the state and local level is recorded through the State Criminal Alien Assistance Program (SCAAP), which is a combination of stocks and flows that is incomparable to any other measure of inmates. Third, 49 states do not record the immigration statuses of those in prison or convicted. Until recently, these data limitations allowed pundits to say anything about illegal immigrant crime without fear of being fact-checked.
Cato scholars have since published numerous Immigration Research and Policy Briefs to shed light on this topic. Michelangelo Landgrave, a doctoral student in political science at the University of California, Riverside, and I released a paper today that estimates that illegal immigrant incarceration rates are about half those of native-born Americans in 2017. In the same year, legal immigrant incarceration rates are then again half those of illegal immigrants. Those results are similar to what Landgrave and I published for the years 2014 and 2016. We estimated illegal immigrant incarceration rates by using the same residual method that demographers use to estimate the number of illegal immigrants in the United States, only we also applied that method to the prison population. We used the same method to also find that the incarceration rate for young illegal immigrants brought here as children and theoretically eligible for deferred action is slightly below those of native-born Americans.
The second strand of research from Cato looks at criminal conviction rates by immigration status in the state of Texas. Unlike every other state, Texas keeps track of the immigration statuses of convicted criminals and the crimes that they committed. Texas is a wonderful state to study because it borders Mexico, has a large illegal immigrant population, is a politically conservative state governed by Republicans, had no jurisdictions that limited its cooperation with federal immigration enforcement in 2015, and it has a law and order reputation for strictly enforcing criminal laws. If anything, Texas is more serious about enforcing laws against illegal immigrant criminals than other states. But even here, illegal immigrant conviction rates are about half those of native-born Americans – without any controls for age, education, ethnicity, or any other characteristic. The illegal immigrant conviction rates for homicide, larceny, and sex crimes are also below those of native-born Americans. The criminal conviction rates for legal immigrants are the lowest of all.