In a few previous posts (e.g., here and here), prompted by claims of African-American linguist John McWhorter, I examined the various biases and difficulties that plague attempts to see if police kill black suspects at a higher rate than whites. This new article in FiveThirtyEight, though not providing an answer to the problem, shows further complications in the attempt to get answers, so that at present we have no idea if there are racial disparities in who becomes the object of police violence.
Click on the screenshot to read:
There are three ways to compare racial disparities:
1.) Proportion of racial populations who are victims of police violence. As is well known, about 0.096% of black men and boys will be killed by the cops during their lifetime. That compares to 0.039% among whites: a 2.5-fold difference. But this doesn’t mean that blacks are more likely to be killed in police encounters, because they may encounter police more often, even if the “kill rate” is the same among races. Which brings us to the second calculation.:
2.) Proportion of racial populations who are victims of police violence, normalized by the proportion of encounters with police. As McWhorter pointed out, blacks encounter police more than whites, so even if both races experience violence at the same rate per encounter, there could still be a differential mortality of blacks at the hands of the cops, but one that wouldn’t necessarily denote racism. There are some data on this, as the article notes:
One example of an encounter denominator approach is a 2019 study by Roland Fryer, an economist at Harvard. He found that police shoot white, Black and Hispanic Americans whom they’ve stopped at equal rates.3 At first blush, that would seem like evidence that the police are not racially biased — every demographic is being treated equally, after all.
As I pointed out, though, this statistic is not perfect because the types of encounters and their dynamics may differ among races, and you need to control for that, which hasn’t been done But the FiveThirtyEight article adds another complication:
3.) Members of racial groups might be stopped at different rates because of racial bias itself. This is called “collider bias.” There are in fact data suggesting that although the frequency deaths per encounter may not differ among races, blacks and whites may be stopped at different rates. And that, in fact, seems to be the case, as we knew from traffic tickets, a disparity (blacks stopped more often) that disappears after dark when race becomes less evident. And, as the article says, it seems as if blacks are stopped when there is less evidence for stopping them than there is for whites, a difference that would reflect racism:
But we know that police officers are more likely to stop Black and Hispanic people than white ones — and that more of those stops are unfounded. Researchers measure this with something called the “hit rate,” or the rate at which contraband is actually found on the people who were stopped. A lower hit rate implies bias because it means that the decision to search someone was made with less evidence. White people stopped in New York City, for example, were more likely to be carrying a weapon than Black and Hispanic people who were stopped. White drivers stopped by the police were more likely to have contraband than Black and Hispanic drivers nationally.
As political scientists Knox, Will Lowe and Jonathan Mummolo, among others, have pointed out, that complicates Fryer’s findings. All of a sudden, what at first appeared to be equal treatment actually suggests unequal treatment. Because of the initial discrimination in who gets stopped, the sample of stopped people isn’t the same across races. The different hit rate indicates that stopped white people are actually more likely to have contraband, on average, than stopped Black people. In other words, in a world without discrimination in who was stopped — if the Black and white people who were stopped were equally likely to be engaged in criminal activity — you’d see an even bigger disparity in outcomes.
In other words, black people stopped by cops may be less likely to be engaged in criminal activity. To control for this, we need the data about the proportion of blacks versus whites who were observed and stopped or not stopped by police. To get this data seems impossible (you can be stopped for acting suspiciously, or just because you’re black), but the differential “hit rate” suggests that cops are targeting blacks at a higher rate than whites without good reason. And that suggests racial bias. Curiously, I think this is pretty evident when explained in words, but FiveThirtyEight presents the same results graphically—to my mind, not clarifying matters much.
And even if bias doesn’t emerge in the rate of killings, it does come out in other aspects of the justice system, for an encounter with a cop is only the first step in a long chain of events that might culminate in jail. The article gives evidence of bias in the subsequent steps of the process:
Across the U.S., demonstrators have spent the past few weeks protesting against racial disparities in the country’s criminal justice system. There’s plenty of data to back them up: Black and Hispanic people are stopped more frequently, including traffic stops, and are more likely to be arrested. Once stopped, police are more likely to use force against, shoot and kill Black citizens. And then once in jail, Black defendants are more likely to be denied bail, which in turn makes conviction more likely. And when convicted, sentencing is also biased against Black defendants, with Black defendants more likely to be incarcerated.
I haven’t read the links in the previous paragraph, which of course could be themselves biased (for example, is race the only reason why black defendants are more likely to be denied bail, or are there other factors like criminal records or the nature of the crime?). But I think there are enough data to conclude one thing: there is evidence for racism in police practices and in the judicial system, and this must be remedied.
On the main issue of whether black deaths at the hands of police reflect racism, at least in part, we don’t yet know the answer. To rephrase Hitchens’s Razor, what can be asserted without evidence must be buttressed with evidence before it can be accepted.