As all the world knows, reality-TV billionaire Donald Trump has been fired from NBC and various other TV networks have cancelled his beauty pageants over his claims that undocumented Mexican immigrants are disproportionally criminals and rapists. He made the claim when launching his presidential campaign:
When Mexico sends its people, they're not sending their best. They're not sending you. They're not sending you. They're sending people that have lots of problems, and they're bringing those problems with us. They're bringing drugs. They're bringing crime. They're rapists. And some, I assume, are good people.
As it happens, back in 2014 I looked into research analyzing immigration and crime rates. Among other things, I reported:
In fact, most research, such as a 2008 report by University of California sociologist Ruben Rumbaut for the Police Foundation National Conference, finds that immigrants, including undocumented ones, are less prone to crime than are native-born Americans. Rumbaut finds that the incarceration rate of American-born males between 18 and 39 years of age was five times the rate of foreign-born males, and finds similar conclusions in a survey of other studies on the topic….
In 2010, Social Science Quarterly published a study of immigrant populations in America's larger cities. It suggested that "growth in immigration may have been responsible for part of the precipitous crime drop of the 1990s."
A fascinating new study in American Law and Economics Review bolsters these data. That research asks, "What is the Contribution of Mexican Immigration to US Crime Rates? Evidence from Rainfall Shocks in Mexico." The study notes that many undocumented immigrants from Mexico come from poor agricultural regions and when crops are affected by rainfall extremes, more immigrants cross our border. The author, Aaron Chalfin, an Assistant Professor in the School of Criminal Justice at the University of Cincinnati, explains:
In order to identify the effect of immigration on crime, my research leverages two empirical regularities with respect to Mexican immigration to the United States. First, migrants from a given Mexican state tend to settle in US cities that have longstanding cultural ties to that state. For example, migrants from states in eastern Mexico have tended to settle in cities in Texas and the Midwest. On the other hand, migrants from western Mexico have tended to settle in California. Second, migrants tend to be drawn disproportionately from regions of Mexico that are heavily reliant on agriculture. As a result, they are more likely to migrate to the United States in the aftermath of sufficiently extreme weather variation – in particular, extreme rainfall.
As it turns out, weather variation in different Mexican regions has implications for the magnitude of historical flows of migrants to US cities. In particular, US cities experience increases in Mexican migration when Mexican states to which they are culturally linked experience highly variable rainfall. Accordingly Mexican rainfall acts like a random assignment mechanism that assigns a different number of annual migrants to each US city.
What does he conclude?
My findings indicate that Mexican immigration is associated with no appreciable change in the rates of either violent or property crimes in U.S. cities.
Somehow I doubt that data will have any effect on Trump's nativistic claptrap.