If I asked you whether or not immigration increases mustard consumption you would probably point that it depends on where the immigrants come from. Now, granted, I could look at whether or not the “average immigrant” eats more mustard than the average non-immigrant, find that the typical immigrant eats less mustard than the average nonimmigrant and, on these grounds, say that immigration typically does not increase mustard consumption

While technically true, this is a somewhat strange way to talk about things. Moreover, if, on these grounds, I reasoned that immigration from a nation known for its high level of mustard consumption would decrease mustard consumption too, well, you probably would not think that I am very bright.

After all, immigration just refers to the movement of a group of people from one area to another. Because not all populations are the same, some eat more mustard than others, the impact of “immigration” obviously depends on who is moving where.

This same logic applies to crime. Whether or not immigration increases crime depends on who is immigrating and where they are immigrating to. Some populations have higher crime rates than others. If a high crime group moves to a low crime area, crime will probably rise. If a low crime group moves to a high crime area, crime will probably fall.

This is all so obvious it is vapid, but this logic is totally ignored when people say things like “studies show immigrants have lower crime rates than natives.”

Of course, in the United States, such studies are typically cited in response to fears about Mexican immigration. Given that Mexicans only make up 28% of American immigrants, inferring facts about Mexican immigrants from statistics about all immigrants is clearly invalid.

If you look at the relevant government data, it turns out that Mexican immigrants are 2.99 times more likely than average to be incarcerated (1). This figure drops to 2.73 if we exclude criminals in federal prisons for immigration-related offenses (2).

That Mexican immigrants commit more crime than other Americans should be totally unsurprising. Mexico’s murder rate is over 4 times that of the United States (3). If you import people from a nation with four times your murder rate, they are probably going to raise your crime rate.

Even broadening the scope of the data to include all Hispanics, we can see that they are clearly overrepresented as a proportion of violent criminals (4).

In fact, young Hispanic males are almost three times more likely than young White males to be end up in jail (5).

To return to the point of this article, the “average immigrant” may be less criminal than the average non-immigrant, but the same is not true for the average Mexican immigrant or the average Hispanic American. Citing studies on “immigrants” is not a valid response to concerns people have about a particular subset of immigrants.

Notes:

1. This calculation was made by dividing the number of Mexican immigrants/non-(Mexican immigrants) in federal/state/local jails by their total population sizes and then comparing the proportion of each population which was in jail. Numbers for the total number of Americans came from the census. The total number of Mexican immigrants was taken from Pew. The number of Mexican immigrants in federal/state/local jail was taken from the Government Accountability Office. The total number of people incarcerated was taken from the Bureau of Justice Statistics.

2. The number of people in federal prison for immigration-related crimes was taken from the Bureau of Justice Statistics.

3. Data on intentional homicide rate by country was taken from the World Bank.

4. Crime data from the 2015 Unifrom Crime Report. General population data from the census.

5. Data on incarceration by ethnicity, age, and sex, was taken from the Justice Department’s “Prisoners in 2014” report.