Cited by 552Policing Practices and PerceptionsCriminal Justice and Corrections AnalysisEducation Discipline and Inequality

The DOI matches its Crossref record; 46 of the 46 references it cites were found in a registry or an index; 4 of the 17 sources its claims cite were checked for support.

A large-scale analysis of racial disparities in police stops across the United States

Open access
Pierson, Emma, Simoiu, Camelia, Overgoor, Jan, Corbett-Davies, Sam, Jenson, Daniel, Shoemaker, Amy, Ramachandran, Vignesh, Barghouty, Phoebe, Phillips, Cheryl, Shroff, Ravi, Goel, Sharad·2020·Nature Human Behaviour

Abstract

We assessed racial disparities in policing in the United States by compiling and analysing a dataset detailing nearly 100 million traffic stops conducted across the country. We found that black drivers were less likely to be stopped after sunset, when a 'veil of darkness' masks one's race, suggesting bias in stop decisions. Furthermore, by examining the rate at which stopped drivers were searched and the likelihood that searches turned up contraband, we found evidence that the bar for searching black and Hispanic drivers was lower than that for searching white drivers. Finally, we found that legalization of recreational marijuana reduced the number of searches of white, black and Hispanic drivers-but the bar for searching black and Hispanic drivers was still lower than that for white drivers post-legalization. Our results indicate that police stops and search decisions suffer from persistent racial bias and point to the value of policy interventions to mitigate these disparities.

Overview

Integrity signals

Registry

Crossref · 10.1038/s41562-020-0858-1

Cites

46 of 46 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

38 Own result · 17 Own method · 14 Own interpretation · 8 Sources not found · 3 Partly supported · 3 No basis given · 2 No full text of the sources · accuracy not yet measured

Show all 35 claims

  • Probably not a substantial claim. 17
  • It may state two separate claims as one. 38
  • The quote only partly states this claim. 2
50 of 50
  • The authors state this as an assumption.

    Officers exercise discretion in whom to search.

    “Implicit in this test is the assumption that officers exercise discretion in whom to search”
  • The authors state this as an assumption.

    In the absence of discrimination, searched minority drivers should be found with contraband at the same rate as searched white drivers.

    “Becker argued that even if minority drivers are more likely to carry contraband, in the absence of discrimination, searched minorities should still be found to have contraband at the same rate as searched whites.”
  • The authors state this as an assumption.

    Officers who engage in racial profiling are less able to identify a driver's race after dark than during the day.

    “Their method starts from the idea that officers who engage in racial profiling are less able to identify a driver's race after dark than during the day.”
  • The paper relies on this without support.

    Race-specific driving behaviour is not related more to lighting than to time of day.

    “Results could be skewed if race-specific driving behaviour is related more to lighting than time of day, leading the test to suggest discrimination where there is none.”
  • The paper relies on this without support.

    Artificial lighting does not substantially weaken the relationship between sunlight and visibility.

    “artificial lighting (for example, from street lamps) can weaken the relationship between sunlight and visibility, and so the method may underestimate the extent to which stops are predicated on perceived race.”
  • The paper relies on this without support.

    Violation type is not related to lighting in a way that biases the veil-of-darkness test.

    “if violation type is related to lighting, the test could give an inaccurate measure of discrimination.”
  • The paper relies on this without support.

    Search policies do not differ within the geographic subdivisions considered.

    “if search policies differ not only across, but also within, the geographic subdivisions we consider, then the threshold test might mistakenly indicate discrimination where there is none.”
  • The paper relies on this without support.

    Officers do not disproportionately suspect more serious criminal activity when searching black and Hispanic drivers than when searching white drivers.

    “if officers disproportionately suspect more serious criminal activity when searching black and Hispanic drivers compared to white drivers (for example, possession of larger quantities of contraband), then lower observed thresholds may stem from non-discriminatory police practices.”
  • The paper relies on this without support.

    The Bayesian threshold model's functional form and prior distributions are adequate for identifying search thresholds.

    “thresholds cannot be identified by the observed data alone 7 , and so inferences are dependent on the specific functional form of the underlying Bayesian model, including the prior distributions.”
  • The paper relies on this without support.

    Marijuana legalization in Colorado and Washington was not confounded by other simultaneous changes, and parallel trends hold.

    “Using a difference-in-differences strategy, we find that legalization reduced both search rates and misdemeanour rates for drug offences for white, black and Hispanic drivers-though a gap in search thresholds persists.”
  • The authors state this as an assumption.

    The latent signal distributions for each race and county are homoskedastic discriminant distributions.

    “these signal distributions are modelled as homoskedastic discriminant distributions, a class of logit-normal mixture distributions supported on the unit interval [0, 1].”
  • The authors state this as an assumption.

    The parameters φ and δ can be decomposed into additive race and location terms.

    “We impose additional structure on the signal distributions by assuming that ϕ r,d and δ r,d can be decomposed into additive race and location terms.”
  • The authors state this as an assumption.

    For each stop, a signal is drawn from the race-and-location-specific distribution; a search occurs if the signal exceeds the race-and-location-specific threshold; if searched, contraband is found with probability equal to the signal.

    “For each stop i, we draw a signal p i from the associated race-and location-specific discriminant distribution.If the signal p i exceeds the race-and location-specific threshold t ri;di I , then a search is conducted and S i = 1; otherwise there is no search and S i = 0.If a search is conducted, contraband is found with probability p i , in which case H i = 1; otherwise, H i = 0.”
  • The paper relies on this without support.

    Recreational marijuana legalization took effect on 9 December 2012 in Washington and 10 December 2012 in Colorado.

    “Measures legalizing recreational marijuana took effect on 9 December 2012 in Washington, and on 10 December 2012 in Colorado.”
  • The paper relies on this without support.

    In Washington, probable cause searches are barred because the state does not have an automobile exception for warrantless searches.

    “in Washington, we note that probable cause searches are barred because the state does not have an automobile exception for warrantless searches.”
15 of 15

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Citations

Cites

Show all 42 references

Research works printed but not linked: 4

  1. Pierson, E., Corbett-Davies, S. & Goel, S. In International Conference on Artificial Intelligence and Statistics (eds Storkey, A. & Fernando Perez-Cruz, F.) 96–105 (PMLR, 2018).
  2. Jung, J., Concannon, C., Shroff, R., Goel, S. & Goldstein, D.G. Simple rules to guide expert classifications. J. R. Stat. Soc. Ser. A (in the press).
  3. Arrow, K. in Discrimination in Labor Markets (eds Ashenfelter, O. & Rees, A.) 3–33 (Princeton Univ. Press, 1973).
  4. Phelps, E. The statistical theory of racism and sexism. Am. Econ. Rev. 62, 659–661 (1972).

Cited by

Sorted by citations

Items 101–200 of 548

Metadata

Authors
Pierson, E., Simoiu, C., Overgoor, J., Corbett-Davies, S., Jenson, D., Shoemaker, A., Ramachandran, V., Barghouty, P., Phillips, C., Shroff, R., & Goel, S.
Affiliations
  • Stanford University (US)
  • New York University (US)
Corresponding author
Goel, Sharad
Venue
Nature Human Behaviour
Published
2020-05-04
Volume
4
Issue
7
Pages
736-745
ISSN
2397-3374 (ISSN-L)
OpenAlex
W2705765409
Cited by
552
References
42
Citations by year
2026: 59 · 2025: 74 · 2024: 97 · 2023: 109 · 2022: 79 · 2021: 71 · 2020: 34
FWCI
254.50
Type
journal article
Language
en
Open access
Locations
  • Nature Human Behaviour (publishedVersion)
  • PubMed (publishedVersion)
  • arXiv (Cornell University) (submittedVersion)
  • RePEc: Research Papers in Economics (submittedVersion)
  • arXiv (Cornell University)
Funders
  • John S. and James L. Knight Foundation
  • Hellman Foundation
Topics
  • Social Sciences › Political Science and International Relations › Policing Practices and Perceptions
  • Social Sciences › Sociology and Political Science › Criminal Justice and Corrections Analysis
  • Social Sciences › Education › Education Discipline and Inequality
Keywords
racial disparities in policing, traffic stops, police searches, racial bias, Black drivers, recreational cannabis legalization, contraband, racial profiling, United States
MeSH terms
Automobile Driving, Black or African American, Female, Hispanic or Latino, Humans, Male, Time Factors, United States, Police, White People, Racism

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