Statistical Methods
We work hard to improve measurement and quantitative research in policing, especially on the difficult problem of quantifying racial bias. The field of policing research is in need of rigorous statistical analysis: traditional research methods struggle to disentangle correlation from causation and often ignore well-known issues like selection bias. Sparse data has led to scattershot analytic approaches across multiple disciplines, making it difficult to reconcile seemingly conflicting results. We work to systematize policing research using modern statistical frameworks and techniques so the field can advance.
Published:
Dean Knox. Science. 2021.
Toward a General Causal Framework for the Study of Racial Bias in Policing
Dean Knox and Jonathan Mummolo. Journal of Political Institutions and Political Economy. 2020.
Making Inferences About Racial Disparities in Police Violence
Dean Knox and Jonathan Mummolo. Proceedings of the National Academy of Sciences. 2020.
Administrative Records Mask Racially Biased Policing
Dean Knox, Will Lowe, and Jonathan Mummolo. American Political Science Review. 2020.
In Progress:
Dean Knox, Will Lowe, and Jonathan Mummolo. Working Paper.
Policy Evaluation
We evaluate policy interventions to see how they affect policing outcomes.
Published:
The Economics of Policing and Public Safety
Bocar Ba and Emily Owens. Journal of Economic Perspectives. 2021.
How Many Complaints Against Police Officers Can Be Abated by Incapacitating a Few “Bad Apples?”
Aaron Chalfin and Jacob Kaplan. Criminology & Public Policy. 2021.
The Role of Officer Race and Gender in Police-Civilian Interactions in Chicago
Bocar Ba, Dean Knox, Jonathan Mummolo, and Roman Rivera. Science. 2021.
Re-evaluating Police Militarization
Jonathan Mummolo. Nature Human Behavior. 2020.
Disparities in Police Award Nominations: Evidence from Chicago
Bocar Ba, Nayoung Rim, and Roman Rivera. American Economic Association Papers and Proceedings. 2020.
Aaron Chalfin and Jacob Kaplan. Criminology & Public Policy. 2019.
Militarization Fails to Enhance Police Safety or Reduce Crime but May Harm Police Reputation
Jonathan Mummolo. Proceedings of the National Academy of Sciences. 2018.
Modern Police Tactics, Police-Citizen Interactions, and the Prospects for Reform
Jonathan Mummolo. The Journal of Politics. 2018.
In Progress:
Police Officer Assignment and Neighborhood Crime
Pat Bayer, Bocar Ba, Nayoung Rim, Roman Rivera, and Modibo Sidibe. Working Paper.
The Black-White Recognition Gap in Award Nominations
Bocar Ba, Nayoung Rim, and Roman Rivera. Working Paper.
Which Police Departments Want Reform? Barriers to Evidence-Based Policymaking
Samantha Goerger, Jonathan Mummolo, and Sean Westwood. Working Paper.
Peer Effects in Police Use of Force
Bocar Ba, Justin Holz, and Roman Rivera. Working Paper.
The Effect of Police Oversight on Crime and Allegations of Misconduct: Evidence from Chicago
Bocar Ba and Roman Rivera. Working Paper.
Hot Temperatures, Aggression, and Death at the Hands of the Police: Evidence from the U.S.
Sebastien Annan-Phan and Bocar Ba. Working Paper.
Bocar Ba. Working Paper.
Public Opinion and Public Education
We engage in research on how the mass public perceives policing and crime, as well as in public-facing education so academics and the general public understand the issues involved and have the best information available. This includes setting the academic and public record straight in instances of flawed research and misinformation.
Published:
How Missing Data Makes It Harder to Measure Racial Bias in Policing
Sujata Gupta. ScienceNews. 2021.
Wharton Professor Wins NOMIS & Science Young Explorer Award
Sejin Park. The Daily Pennsylvanian. 2021.
Wharton Professor Dean Knox Recipient of 2021 NOMIS & Science Young Explorer Award
Walter Beckwith. Science Magazine. 2021.
Mummolo Receives Microsoft Funding for Police Body-Worn Camera Project
Riis L. Williams. Princeton School of Public and International Affairs. 2021.
Bocar Ba Rejoins Duke Faculty, Continues Research on Economics of Crime and Labor
Elizabeth Richardson. Duke Department of Economics. 2021.
Laura McCrystal and David Gambacorta. The Philadelphia Inquirer. 2021.
Police Advisory Commission. City of Philadelphia. 2021.
Report: Less than 1% of Civilian Complaints Filed Against Philly Police Result in Discipline
Aaron Moselle. WHYY. 2021.
Study: Police Diversity Matters
Douglas Starr. Science. 2021.
Diversity in Policing Can Improve Police-Civilian Interactions
B. Rose Huber. Princeton School of Public and International Affairs. 2021.
Law Enforcement Diversity May Improve Policing, Study Shows
Christine Fernando and Marion Renault. Associated Press. 2021.
Countering Police Bias with Data
Bianca Ortiz-Miskimen. Discovery: Research at Princeton. 2021.
Tech Firms Hire ‘Red Teams.’ Scientists Should, Too
Adam Marcus and Ivan Oransky. WIRED. 2020.
A Widely Touted Study Found No Evidence of Racism in Police Shootings. It’s Full of Errors.
Dean Knox and Jonathan Mummolo. The Washington Post. 2020.
Prominent Claims that Policing is Not Racially Biased Rest on Flawed Science
Dean Knox and Jonathan Mummolo. Medium. 2020.
Why Statistics Don’t Capture the Full Extent of the Systemic Bias in Policing
Laura Bronner. FiveThirtyEight. 2020.
Police Think They Can Get Away with Anything. That’s Because They Usually Do.
Bocar Ba and Roman Rivera. The Washington Post. 2020.
It Took Us Months to Contest a Flawed Study on Police Bias. Here’s Why That’s Dangerous.
Dean Knox and Jonathan Mummolo. The Washington Post. 2020.
Making Inferences about Racial Disparities in Police Violence
Dean Knox and Jonathan Mummolo. Proceedings of the National Academy of Sciences. 2020.
Militarization Fails to Enhance Police Safety or Reduce Crime but May Harm Police Reputation
Jonathan Mummolo. Proceedings of the National Academy of Sciences. 2018.
In Progress:
Jane Esberg, Jonathan Mummolo, and Sean Westwood. Submitted.
Explaining Misperceptions of Crime
Jane Esberg and Jonathan Mummolo. Working Paper.