This is Naked Capitalism fundraising week. 1132 donors have already invested in our efforts to combat corruption and predatory conduct, particularly in the financial realm. Please join us and participate via our donation page, which shows how to give via check, credit card, debit card, or PayPal. Read about why we’re doing this fundraiser, what we’ve accomplished in the last year, and our fifth target, more original reporting.
Yves here. I managed to miss this post by Rajiv Sethi last week, and I thought it was important to make up for that oversight. It illuminates one of our underlying themes: the importance to look at data and analyses critically. Here Sethi takes a plausible-seeming study and scotches it by virtue of exposing and challenging a hidden assumption. And the delay proved to be useful as Sethi updated his post based on correspondence with the author of the article he criticized as well as others who took interest in it.
By Rajiv Sethi, Professor of Economics, Barnard College, Columbia University. Cross posted from his blog.
Sendhil Mullainathan is one of the most thoughtful people in the economics profession, but he has a recent piece in the New York Times with which I really must take issue.
Citing data on the racial breakdown of arrests and deaths at the hands of law enforcement officers, he argues that “eliminating the biases of all police officers would do little to materially reduce the total number of African-American killings.” Here’s his reasoning:
According to the F.B.I.’s Supplementary Homicide Report, 31.8 percent of people shot by the police were African-American, a proportion more than two and a half times the 13.2 percent of African-Americans in the general population… But this data does not prove that biased police officers are more likely to shoot blacks in any given encounter…
Every police encounter contains a risk: The officer might be poorly trained, might act with malice or simply make a mistake, and civilians might do something that is perceived as a threat. The omnipresence of guns exaggerates all these risks.
Such risks exist for people of any race — after all, many people killed by police officers were not black. But having more encounters with police officers, even with officers entirely free of racial bias, can create a greater risk of a fatal shooting.
Arrest data lets us measure this possibility. For the entire country, 28.9 percent of arrestees were African-American. This number is not very different from the 31.8 percent of police-shooting victims who were African-Americans. If police discrimination were a big factor in the actual killings, we would have expected a larger gap between the arrest rate and the police-killing rate.
This in turn suggests that removing police racial bias will have little effect on the killing rate.
A key assumption underlying this argument is that encounters involving genuine (as opposed to perceived) threats to officer safety arise with equal frequency across groups. To see why this is a questionable assumption, consider two types of encounters, which I will call safe and risky. A risky encounter is one in which the confronted individual poses a real threat to the officer; a safe encounter is one in which no such threat is present. But a safe encounter might well be perceived as risky, as the following example of a traffic stop for a seat belt violation in South Carolina vividly illustrates:
Sendhil is implicitly assuming that a white motorist who behaved in exactly the same manner as Levar Jones did in the above video would have been treated in precisely the same manner by the officer in question, or that the incident shown here is too rare to have an impact on the aggregate data. Neither hypothesis seems plausible to me.
How, then, can one account for the rough parity between arrest rates and the rate of shooting deaths at the hands of law enforcement? If officers frequently behave differently in encounters with black civilians, shouldn’t one see a higher rate of killing per encounter?
Not necessarily. To see why, think of the encounter involving Henry Louis Gates and Officer James Crowley back in 2009. This was a safe encounter as defined above, but may not have happened in the first place had Gates been white. If the very high incidence of encounters between police and black men is due, in part, to encounters that ought not to have occurred at all, then a disproportionate share of these will be safe, and one ought to expect fewer killings per encounter in the absence of bias. Observing parity would then be suggestive of bias, and eliminating bias would surely result in fewer killings.
In justifying the termination of the officer in the video above, the director of the South Carolina Department of Public Safety stated that he “reacted to a perceived threat where there was none.” Fear is a powerful motivator, and even when there are strong incentives not to shoot, it is still a preferable option to being shot. This is why stand-your-ground laws have resulted in an increased incidence of homicide, despite narrowing the very definition of homicide to exclude certain killings. It is also why homicide is so volatile across time and space, and why staggering racial disparities in both victimization and offending persist.
None of this should detract from the other points made in Sendhil’s piece. There are indeed deep structural problems underlying the high rate of encounters, and these need urgent policy attention. But a careful reading of the data does not support the claim that “removing police racial bias will have little effect on the killing rate.” On the contrary, I expect that improved screening and better training, coupled with body and dashboard cameras, will result in fewer officers reacting to a perceived threat when there is none.
Update (10/18). I had a useful exchange of emails with Sendhil yesterday. I think that we both care deeply about the issue and are interested in getting to the truth, not in scoring points. But there’s no convergence in positions yet. Here’s an extract of my last to him (I’m posting it because it might help clarify the argument above):
Definitely you can easily make sense of the data without bias. The question is whether this is the right inference, given what we know about the processes generating encounters.
Suppose (for the sake of argument) that whites have encounters with police only if they are engaging in some criminal activity, while blacks sometimes have encounters with police when they are completely innocent. This need not be due to police bias: it could be because bystanders are more likely to think blacks are up to no good for instance (Gates and Rice come to mind).
Suppose further that those engaging in criminal activity are threats to the police with some probability, and this is independent of offender race. The innocents are never threats to the police. But cops can’t tell black innocents from black criminals, so end up killing blacks and whites at the same rate per encounter. If they could tell them apart, blacks would be killed at a lower rate per encounter. What I mean by bias is really this inability to distinguish; to see threats when none are present.
I believe that black cops are less likely than white cops to perceive an encounter with an innocent as threatening. If a suspect looks like your cousin, or a guy you sit beside to watch football on Sundays, you are less likely to see him as a threat when he is not. That’s why I asked you in Cambridge whether you had data on officer race in killings – when the victim is innocent the officer seems invariably to be white. So a first very rough test of bias would be whether innocents are killed at the same rate by black and white officers…
I’ve found the twitter reaction to your post a bit depressing, because better selection, training and video monitoring are really urgent needs in my opinion, and the absence-of-bias narrative can feed complacency about these. I know that was far from your intention, and you are extremely sympathetic to victims of police (and other) violence. You also have a responsibility to speak out on the issue, given your close scrutiny of the data. But I do believe that the inference you’ve made about the likely negligible effects of eliminating police bias are not really supported by the evidence presented. That, and the personal importance of the issue to me, compelled me to write the response.
Update (10/19). This post by Jacob Dink is worth reading. Jacob shows that the likelihood of being shot by police conditional on being unarmed is twice as high for blacks relative to whites. The likelihood is also higher conditional on being armed, but the difference is smaller:
This, together with the fact that rates of arrest and killing are roughly equal across groups, implies that blacks are less likely to be armed than whites, conditional on an encounter. In the absence of bias, therefore, the rate of killing per encounter should be lower for blacks, not equal across groups. So we can’t conclude that “removing police racial bias will have little
effect on the killing rate.” That was the point I was trying to make in this post.
Update (10/21). Andrew Gelman follows up. The link above to Jacob Dink’s post seems to be broken and I can’t find a cached version. But there’s a post by Howard Frant from earlier this year that makes a similar point.
13 comments
Comments are closed.
Great read on such an important topic. If I could add another dot to connect more explicitly, some of the miscommunication or differing assumptions is about what constitutes racism. Are we talking about specific biases of individual officers, or systemic injustice and oppression?
Because the latter is interconnected with poverty when talking in aggregate. Since 1) wealth is not randomly distributed (in aggregate, white households are wealthier than black households) and 2) the systemic purpose of law enforcement is to keep the lower classes in line (as it is euphemistically described, to maintain order and promote public safety) then we would expect more blacks to be subject to encounters with law enforcement, and more of those encounters to include force, regardless of the biases of individual officers.
Thus, changing the biases of individual officers, while not a useless endeavor, is a rather small part of the issue. As long as society is extremely unequal, and as long as the role assigned to police is to maintain that inequality, blacks in the US will face a higher risk of being shot than whites.
The racism and injustice is systemic. It comes from the top. It matters very little how any one low level officer on patrol feels. The very patrols to which they are assigned differ based upon the wealth and power of the people targeted.
Seriously? The purpose of police is not to oppress black people. Yes there are those officers who are extremely prejudiced. However, there needs to be law and order. Those same black people accusing the police of prejudice are quick to call the police when in trouble. Maybe if there was better dialogue. Your assumption that there are more poor blacks than whites is also flawed. There are plenty of poor whites. Maybe if you got outside of your bubble you would see that.
Well, now that we slavery’s no longer outlawed, sure.
You write: “Those same black people accusing the police of prejudice are quick to call the police when in trouble.”
I hear that argument a lot. I’m not sure why the trade-off for cops doing their jobs as law enforcement officers (modulo them acting in “law enforcement for profit” mode, as in St Louis and elsewhere) has to be allowing them to whack black people with impunity. Perhaps you can elucidate?
“Every police encounter contains a risk: The officer might be poorly trained, might act with malice or simply make a mistake, and civilians might do something that is perceived as a threat. The omnipresence of guns exaggerates all these risks.
Such risks exist for people of any race — after all, many people killed by police officers were not black. But having more encounters with police officers, even with officers entirely free of racial bias, can create a greater risk of a fatal shooting.
……
Sendhil is implicitly assuming that a white motorist who behaved in exactly the same manner as Levar Jones did in the above video would have been treated in precisely the same manner by the officer in question, or that the incident shown here is too rare to have an impact on the aggregate data. Neither hypothesis seems plausible to me.”
….
How, then, can one account for the rough parity between arrest rates and the rate of shooting deaths at the hands of law enforcement? If officers frequently behave differently in encounters with black civilians, shouldn’t one see a higher rate of killing per encounter?
Not necessarily. To see why, think of the encounter involving Henry Louis Gates and Officer James Crowley back in 2009. This was a safe encounter as defined above, but may not have happened in the first place had Gates been white. If the very high incidence of encounters between police and black men is due, in part, to encounters that ought not to have occurred at all, then a disproportionate share of these will be safe, and one ought to expect fewer killings per encounter in the absence of bias. Observing parity would then be suggestive of bias, and eliminating bias would surely result in fewer killings.
============================================
This is a very good article with lots of good points.
However, I would also point out that the very data that goes into the system is undoubtedly skewed, for example the term “encounter” and its use if problematic – if the police spend a disproportionate amount of time simply OBSERVING blacks disproportionately and more stringently, than encounters, arrests, and shooting undoubtedly will increase. Police will assert that blacks commit more crimes which is why they are observed so much, but it is just as plausible that a crime can be found for every arrest…(and the police, like every bureaucracy, will justify itself).
So
“eliminating the biases of all police officers would do little to materially reduce the total number of African-American killings.”
Sethi disagrees with that – I do not entirely disagree, (I think eliminating all biases of the police would have a salutary effect and reduce killings) but I ALSO believe that the government POLICY of war on drugs, turning an entire race into documented felons which makes them career criminals, also has a significant effect in addition to bias (of course, bias leads to policy, but that is the politicians do that, not the police directly). If your policy is repression, than your gonna get resistance, and that resistance is met with a policy of state violence.
Regarding Henry Louis Gates’ example, I always find it odd that people assume Noam Chomsky could’ve been in the same situation yelling about class and would not have been arrested. It’s the problem of the single example: we can impose any narrative on it.
As for the general issue, when you factor in class, the suggestion of racial bias becomes much smaller: the people who are killed by the police tend to be poor, poverty in the US is about 1/3 black and 2/3 white, and the people killed by the police are about 1/3 black and 2/3 white.
Chomsky would never have been yelling about anything because the officer would never have bothered to even talk to him.
There was a report of someone trying to break into a home, so the cop would’ve had to talk to him.
I also suspect Chomsky would not have expected his social status to protect him, as it seems Gates did, so Chomsky prob’ly would’ve been more deferential.
Mind you, I admire Gates. But the guy’s a classic liberal, so he had no choice but to assume he would’ve been treated better had he been white.
There was a report of someone trying to break into a home, so the cop would’ve had to talk to him.
But the cops would not have been called for Chomsky. It isn’t just the police that over-react to nonexistent threats
“But the guy’s a classic liberal, so he had no choice but to assume he would’ve been treated better had he been white.”
Someone has never heard of white privilege, I guess.
I think racializing what are really class issues has worked out very well for the ruling class, academia, the media, and better-off people in general, so it’s unlikely we’ll see significant changes in what kind of people the police shoot any time soon.
there is no “POLICE”, there are individuals who are Law Enforcement Officers. Almost all of them badly handled by politically connected inept management who are the real problem in 75% of the unprofessional encounters. HR in Police Dept’s want stressed out financially challenged individuals who will not question stupid ideas. One also has to remember…there is a monster anti-union movement in the United States and Police are one of the last STRONG UNIONS in the US of A…
and then we get the intellectually ridiculous uber-left stupid stuff…Gates was looking to help sell his “new book” and took the opportunity to force an escalation of the situation…yes some crazy white lady called cause she saw a “negro” in her episcopalian/methodist “community”…but Gates took it as an opportunity, knowing the college town police would not just put 2 bullets in the back of his head over mouthing off a bit…Mumia knows damn well who shot that Police Officer…no it was not Mumia, but he thinks refusing to cooperate in a Police killing sends a message…yeah…it gives a license to bullies and sadists with a badge and a gun to relive junior high school and pick on someone…in the case of modern america, broke black folk…
there is a lot of noise that goes on in the world…I have more than my share of friends and family in law enforcement so I have a general idea of the childish stresses they are under “to produce”…I tend to tone down (tend to…not always) any situation with a police officer…I tend to roll down my window in a traffic stop…shut off my car…take the ignition keys and loop it thru a pinky…take my wallet out and keeping both hands out the window…reach into the wallet and pull out my license registration and insurance in full view and have it ready to hand off before asked…and then I keep my hands hanging out the window with wallet in hand during the entire encounter…why…because the law enforcement officer is trained to deal with potential issues…one being, where are the hands of the person…where are the keys…is the car running so that a potential, no matter how remote, chase might occur…
all that having been said, the direction of the article by Prof Sethi is quite correct…there is a Bernaze sauce to a large amount of “scientific” information…with conclusions drawn that when put under the light make almost zero sense to anyone who can fog up a mirror and tie their own shoe laces…
(people still tie shoe laces, yes ??)
a prefect example is the nonsense around “broken window” police policy…a badly skewed situation that I may have had a sad part in “popularizing” during the early Clinton Administration…most of the studies point back to one individual who grew up in a mob controlled area of the Bronx…Arthur Avenue…he had a “piece” covered by TIME magazine…where he claimed to leave a car and folks just stripped it…mind you, one of the fun things is that no blacks or hispanics were “photographed”…but you know…like reagan and his “south side of chicago” welfare queen…nod wink…”you know what I am saying” and most people feed into their self created fears…even when it turns out reagans welfare queen was a white woman…and in that same vein…a car was left on a street in the south bronx…and you know those south bronx people…but beyond the fact the people were white who were stripping the car and that was “glossed” over…I don’t think it actually happened…the professional academic who wrote that and then another item about prisoners and the killing of guards by these “dangerous” ghetto people…my studies and experience suggest he is a three letter agency funded guy…that prison study in california that he went on the media with…he never mentions it was a famous black panthers event…one would think if you were trying to claim this was an average, normal risk for police..it might be intellectually honest to point out it was a hostage crisis with international manhunts for an attorney who was set up and shots and guns that were never properly and fully investigated…the three letter professional academic is still around…I reached out thru his website asking about trying to get a copy of his “car stripping” report/study in the bronx original claim to fame piece…still hearing the crickets…
that car stripping story in TIME…my studies and experience led me to question the camera angles and the tree…the good prof who used that placed piece produced for TIME a few photos…but the camera seems to have moved…and three tree limbs seemed to have grown…suggesting this was not a car stripping that happened in a few hours…but one that happened over a much larger period of time…and there are other visual problems with the photo…but I will leave that for others with IVY league credentials to question…for now this humble lovable shoe shine boy has to go back to his creating money for paying of bills…
@Alex – thx for the entertaining and incisive storytelling it like it is. Reality is both more mundane and more greasy and delicious than our exalted ideas would have it, eh?
Excellent article. It points to the fallacy underlying the reports by two “experts” (a former FBI agent and a prosecutor) released by the Cleveland DA regarding the shooting of 12-year old Tamir Rice.
These experts concluded that the officer who killed Tamir acted reasonably even though he shot the boy within seconds of arriving on the scene. They claimed the officer couldn’t have discerned that Tamir was a child (in few seconds before he shot him) and justifiably felt threatened when Tamir approached him.
Does anyone truly believe that the officer would have acted the same way (shoot first, as questions later) had it been a white boy with a toy gun? And, assuming he thought Tamir was older, there is such a thing as the 2nd Amendment. Shouldn’t the officer have inquired whether the black man with the gun had a permit? (And why haven’t all the Open Carry Crazies come out in defense of Tamir’s right to have a gun?)