You just know that a study is going to be unbiased when it opens with a quote from Donald Trump from 2015 in which he said, “When Mexico sends its people, they’re not sending their best.”
Once having gotten that out of their system, associate sociology professor Robert Adelman and his team at the University of Buffalo get busy trying to prove that there is no link between immigration and crime rates. In order to make their case, Adelman et. al. examine census data and uniform crime data from the FBI over a 40-year period, 1970 to 2010.
Adelman offers the caveat that the relationship between immigration and crime is complex and that more research needs to be done. Amen to that.
The question of whether the team’s findings confirm their hypotheses is rendered moot by a fundamental flaw. Namely, the study proceeds from an invalid assumption. No one, including Donald Trump, has argued that allowing citizens of foreign nations to emigrate to this one through legal channels leads to more crime. The real issue is whether foreigners who enter the U.S. illegally swell the crime rates. (For the record, the word illegal appears in the study once, in the context of illegal labor markets.)
So, do immigrants who come here illegally increase the rate of crime? Even discounting the crime of illegal entry committed by every fence jumper, the answer is a resounding yes. The matter is so open-and-shut that even PolitiFact was forced to concede in September 2016 that Fox News Channel’s Sean Hannity had spoken the truth when he said that illegal immigrants account for up to 75% of convictions for selected crimes:
In general, those classified as “illegal aliens” accounted for 25,670, or 37 percent, of 70,225 individuals convicted of all federal crimes in the 12 months through September 2015. That includes 18,782 sentenced for immigration offenses.
The “illegal alien” category accounted for the following share of convictions in the crimes cited by Hannity:
• 1,640 of 2,181 total convictions (75 percent) in which the primary charge was simple drug possession.
• 13 of 43 convictions (30 percent) for kidnapping/hostage taking.
• 21 of 100 convictions (21 percent) for “national defense” crimes, which include convictions for exporting arms, munitions or military equipment without a license or providing material support to designated foreign terrorist organizations or for terrorist purposes, per a 2013 commission report.
• 3,555 of 19,989 convictions (18 percent) for drug trafficking.
• 69 of 665 convictions (10 percent of them, for money laundering.
• 5 of 91 convictions, or 5.5 percent, for murder.
The above numbers are easily verified using the same sources — the Census Bureau and FBI Uniform Crime Reporting program — that Adelman et. al. used in their study.