I join my voice to those of Rand Paul and other prominent libertarians who are reacting to the violence in Ferguson, Mo. by calling for the demilitarization of the U.S.’s police. Beyond question, the local civil police in the U.S. are too heavily armed and in many places have developed an adversarial attitude towards the civilians they serve, one that makes police overreactions and civil violence almost inevitable.

But I publish this blog in part because I think it is my duty to speak taboo and unspeakable truths. And there’s another injustice being done here: the specific assumption, common among civil libertarians, that police overreactions are being driven by institutional racism. I believe this is dangerously untrue and actually impedes effective thinking about how to prevent future outrages.

In the Kivila language of the Trobriand Islands there is a lovely word, “mokita”, which means “truth we all know but agree not to talk about”. I am about to speak some mokitas.

Let’s begin with some statistics. Wikipedia has this to say about race and homicide rates:

According to the US Department of Justice, blacks accounted for 52.5% of homicide offenders from 1980 to 2008, with whites 45.3% and Native Americans and Asians 2.2%. The offending rate for blacks was almost 8 times higher than whites, and the victim rate 6 times higher. Most murders were intraracial, with 84% of white homicide victims murdered by whites, and 93% of black victims murdered by blacks.

Moving forward from 2008 or back from 1980 would change these figures very little; I cite Wikipedia because it’s handy, but I already knew them within a couple of percentage points and they’ve been very similar since before I was born in the 1950s. And we can take homicide figures as representative of racial disparities in wider violent crime rates, because – observably – they are.

Now here are some more facts which taken together, change the implications of that 52.5% a lot. First: in any subpopulation, whether chosen by race or SES or any other criterion, almost all violent crime (up to statistical noise) is perpetrated by males between the ages of 15 and 25.

Second: The black population of the U.S., as of the 2010 census, is 12.61% of the total.

Third: Within that population, males 15-25 are approximately 8% of it (add up the 15-19 and 20-24 boxes in table 2 and divide by two to account for the fact that half of that percentage is female). Multiplying these, the percentage of black males 15-24 in the general population is about 1%. If you add “mixed”, which is reasonable in order to correspond to a policeman’s category of “nonwhite”, it goes to about 2%.

That 2% is responsible for almost all of 52% of U.S. homicides. Or, to put it differently, by these figures a young black or “mixed” male is roughly 26 times more likely to be a homicidal threat than a random person outside that category – older or younger blacks, whites, hispanics, females, whatever. If the young male is unambiguously black that figure goes up, about doubling.

26 times more likely. That’s a lot. It means that even given very forgiving assumptions about differential rates of conviction and other factors we probably still have a difference in propensity to homicide (and other violent crimes for which its rates are an index, including rape, armed robbery, and hot burglary) of around 20:1. That’s being very generous, assuming that cumulative errors have thrown my calculations are off by up to a factor of 6 in the direction unfavorable to my argument.

Now suppose you’re a cop. Your job rubs your nose in the reality behind crime statistics. What you’re going to see on the streets every day is that random black male youths are roughly 20 times more likely to be dangerous to you – and to other civilians – than anyone who isn’t a random black male youth.

Any cop who treated members of a group with a factor 20 greater threat level than population baseline “equally” would be crazy. He wouldn’t be doing his job; he’d be jeopardizing the civil peace by inaction.

Yeah, my all means let’s demilitarize the police. But let’s also stop screaming “racism” when, by the numbers, the bad shit that goes down with black male youths reflects a cop’s rational fear of that particular demographic – and not racism against blacks in general. Often the cops in these incidents are themselves black, a fact that media accounts tend to suppress.

What we can actually do about the implied problem is a larger question. (Decriminalizing drugs would be a good start.) But it’s one we can’t even begin to address rationally without seeing past the accusation of racism.