Research | Research on Policing Reform and Accountability

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:

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:

Can Racial Bias in Policing Be Credibly Estimated Using Data Contaminated by Post-Treatment Selection?

Dean Knox, Will Lowe, and Jonathan Mummolo. Working Paper.

Policy Evaluation

We evaluate policy interventions to see how they affect policing outcomes.

Published:

Diversity in Policing: 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.

More cops, fewer prisoners?

Jacob Kaplan and Aaron Chalfin. 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:

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.

Going the Extra Mile: the Cost of Complaint Filing, Accountability, and Law Enforcement Outcomes in Chicago

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:

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.

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