Home > data science > Is Stop, Question and Frisk racist?

Is Stop, Question and Frisk racist?

December 27, 2011

A few weeks ago I was a “data wrangler” at the first Data Without Borders datadive weekend. My group of volunteer data scientists was exploring the NYPD “Stop, Question and Frisk” data from the previous few years. I blogged about it here and here.

One thing we were interested in exploring was the extent to which this policy, whereby people can be stopped, questioned, and frisked for merely looking suspicious (to the cops) is racist. This is what I said in my second post:

We read Gelman, Fagan and Kiss’s article about using the Stop and Frisk data to understand racial profiling, with the idea that we could test it out on more data or modify their methodology to slightly change the goal. However, they used crime statistics data that we don’t have and can’t find and which are essential to a good study.

As an example of how crucial crime data like this is, if you hear the statement, “10% of the people living in this community are black but 50% of the people stopped and frisked are black,” it sounds pretty damning, but if you add “50% of crimes are committed by blacks” then it sound less so. We need that data for the purpose of analysis.

Why is crime statistics data so hard to find? If you go to NYPD’s site and search for crime statistics, you get really very little information, which is not broken down by area (never mind x and y coordinates) or ethnicity. That stuff should be publicly available. In any case it’s interesting that the Stop and Frisk data is but the crime stats data isn’t.

I still think it is outrageous that we don’t have open source crime statistics in New York, where Bloomberg claims to be such a friend to data and to openness.

And I also still think that, in order to prove racism in the strict sense of the above discussion, we need that data.

However, my overall opinion has changed about whether we have enough data already to say if this policy is broadly racist. It is. My mind changed reading this article from the New York Times a couple of weeks ago. It was written by a young black man from New York, describing his experiences first-hand being stopped, questioned, and frisked. The entire article is excellently written and you should take a look; here’s an excerpt:

For young people in my neighborhood, getting stopped and frisked is a rite of passage. We expect the police to jump us at any moment. We know the rules: don’t run and don’t try to explain, because speaking up for yourself might get you arrested or worse. And we all feel the same way — degraded, harassed, violated and criminalized because we’re black or Latino. Have I been stopped more than the average young black person? I don’t know, but I look like a zillion other people on the street. And we’re all just trying to live our lives.

The argument for this policy is that it improves crime statistics. For some people, especially if they aren’t young and aren’t constant targets of the policy, it’s probably a price worth paying to live in a less crime-ridden area.

And we all want there to be less crime, of course, but what we really want is something even more fundamental, which is a high quality of life. Part of that is not being victimized by crooks, but another part of that is not being (singled out and) victimized by authority either.

I think a good thought experiment is to consider how they could make the policy colorblind. One obvious way is to have cops in every neighborhood performing stop, question and frisk to random people. The argument against this is, of course, that we don’t have enough cops or enough money to do something like that.

Instead, to be more realistic about resources, we could have groups of cops randomly be assigned to neighborhoods on a given day for such stops. If you think the policy is such a good crime deterrent, than you can even weight the probability of a given neighborhood by the crime rate in that neighborhood. (As an aside, I would love to see whether there’s statistically significant reason to believe that this policy does, in fact, deter crime. So often mayors and policies take credit for lowered crime rates in a given city when in fact crime rates are going down all over the country in a kind of seasonality way.) So in this model the cops are more likely to land in a high-crime area, but eventually by the laws of statistics they will visit every neighborhood.

My guess is that, the very first time the Upper East Side is chosen randomly, and a white hedge fund manager is stopped, questioned, and frisked by a cop, who takes away his key and enters his apartment, terrorizing his family while he’s handcuffed in the back of a cop car, is the very last day this policy is in place.

Categories: data science
  1. December 27, 2011 at 8:46 am

    Yes but,…

    From my personal experience of living in London’s Jamaican Community (as a white man in a mixed marriage) and London’s Ashkenazi Jewish community (growing up) I know anecdotally (ie by direct personal experience) that there is much more stop and search on the black community …

    But I also know that there is more street crime and more gun crime in the black community, …

    And I suspect that the police and authorities prioritise which crimes to police according to how easy they are to detect …so they go harder against violent street robbery than against investment banking fraud … even though ultimately both are about relieving old ladies of their pensions.


  2. Scott Kilpatrick
    December 29, 2011 at 4:02 am

    One question is “Can we quantitatively determine that it’s racist?” and another is “Do we want this to happen in our society anyway?” There’s no need to try to quantify something that is demonstrably immoral and harmful to society. Where does this quantification get you? No technocrat will end this sort of policy because of what some model indicates; he’ll end it after mounting pressure from those looking for a more just, equal society. After all, as you make clear in the latter half of this post, it’s a policy that would be quite despised by the public if it *didn’t* target along racial (or at least socioeconomic) boundaries.


  3. Desiree DeLoach
    January 3, 2012 at 9:46 am

    The statistics are this: In the first six months of 2011, 362,150 people were stopped and frisked (it hardly ever involves questioning BEFORE being frisked). Of those stopped, 51% were black, 33% Latino, 9% White, and 7% were of another race. Using the same statistics, 12% were NOT innocent, 88% of them WERE innocent. At the end of the year they had stopped and frisked approximately 700,000, or roughly 2,000 per DAY.

    I believe we have already agreed upon the fact that this policy is racist, but I just wanted to throw out the statistics.

    I am a part of an activist group here in NYC called Stop Stop & Frisk, which goes into the boroughs marching to specific precincts and committing civil disobedience in order to bring attention to this policy. Most of the people within these communities do not need to be educated on what stop and frisk is, they know first hand by either personal experience or by knowing someone that has personal experience. We want them to know that we know this has been going on for a long time, and we are not going away until it has stopped and that we are willing to take on the next form of racial profiling should the policy only be reformed. We are also educating those that are unaware of the policy.

    We have obtained a copy of the UF-250, which is the form in which the NYPD must fill out after stopping and frisking someone. It uses language such as “fits description” (what description?), suspicious bulge, furtive movements, wearing clothes commonly used in commission of crime. From the language here, as well as on the rest of the form, it is clear that this is not about reducing crime, and all about putting our Black and Latino youth through the system and helping advance the school to prison pipeline as well as the prison industrial complex, where there are over 2.4 million incarcerated here in the United States.

    Also, when we look at the race statistics for those that have committed crimes, we cannot stop there, we must look at the broader picture. Who finds it more difficult to get employment, Whites or Blacks and Latinos? Who are more likely to receive a higher salary, Whites or Blacks and Latinos? On top of that they’re being stopped and frisked and often brutalized and jailed when the majority of them are not even doing anything wrong or have yet to commit a crime. Growing up with all of these factors is enough to weigh heavily on the brain and is a vicious cycle that needs to end.

    We are ALL Sean Bell.


  4. March 8, 2012 at 1:47 pm

    I saw this article on how


    numbers of murders were estimated in war zones based on a “catch, release, recatch” type statistical analysis.

    You could do the same thing with stop question and frisk.


  1. March 6, 2012 at 6:20 am
  2. May 20, 2012 at 7:02 am
  3. July 26, 2012 at 7:28 am
  4. August 5, 2013 at 11:20 am
Comments are closed.
%d bloggers like this: