News Release

Community policing and police legitimacy: A field experiment

Peer-Reviewed Publication

Massachusetts Institute of Technology

CAMBRIDGE, Mass., Sept. 16, 2019 - Despite declining crime rates, tensions between police and the public remain an ongoing issue. High-profile incidents of police violence have led to distrust of the police, particularly among residents in high-crime and low-income areas. While some policymakers promote the use of community-oriented policing (COP) to enhance public trust and police legitimacy, little is known about its actual effectiveness. In a recent study, MIT Sloan Prof. David Rand, in collaboration with Kyle Peyton of Yale University and Prof. Michael Sierra-Arévalo of the Rutgers School of Criminal Justice, provide the strongest evidence to date in support of the use of COP.

The study, which combined a randomized field experiment with longitudinal survey measurements, found that a single positive, nonenforcement contact with a uniformed patrol officer substantially improved the public's attitudes towards the police.

"We currently have a crisis of legitimacy, where many residents don't trust police officers, making it harder for them to effectively fight crime. COP's goal is to facilitate positive nonenforcement interactions between police and the public--through things like community meetings and door-to-door visits--to help residents feel safe and build trust. However, no one knows if it actually works and is worth the investment," says Rand.

To measure the effectiveness of COP, the researchers conducted a first-of-its-kind field experiment on the decades-old policing strategy. "We looked at whether positive, nonenforcement contact at the heart of community policing actually causes people to view the police differently," explains Peyton.

First, they mailed out a baseline survey to thousands of residents in New Haven, CT about their attitudes toward parts of the city's government, including the police. They were asked about issues such as:

  • Legitimacy - Do they feel the police make fair and impartial decisions?

  • Performance - Do they have confidence in the police to do their job well?

  • Cooperation - Would they be willing to assist the police in a search for a suspect?

  • Compliance - Would they be willing to do what a police officer tells them to do?

Half of those who completed the baseline survey were then randomly selected to receive an unannounced visit from a police officer. After knocking on the door, the officers introduced themselves and explained they were making a community policing visit in a nonenforcement capacity and provided their work cell phone number via a personalized business card.

The researchers sent follow-up surveys to residents three days and 21 days after the community policing visits, analyzing differences between those who received COP visits and those who did not.

"The findings were striking," says Rand. "There was some skepticism about whether a single COP visit would make a difference, and even concern that such visits could backfire if the residents responded with hostility or distrust. But it turned out to have a big positive impact. The people who received the community policing visits had a much better view of police afterward."

This was true of all of the different kinds of attitudes towards the police that were measured in the study. The effect was also still evident three weeks after the visit.

Importantly, the study found that the positive effects were particularly large for specific demographics. Rand explains,

"Among black respondents who had COP visits, the intervention had nearly twice as large of an effect as among white respondents. Further, the visits had the strongest effects among individuals who held the most negative views toward police prior to the COP visit."

The study also highlighted how the COP visit led to an increase in support for funding for additional police officers and a small decrease in support for body-worn cameras.

"Our research provides evidence in support of the power of COP to improve relationships between the police and residents," says Rand. "These broad effects of positive contact are especially important in light of the documented tensions between the police and the public, particularly within minority communities where longstanding distrust of the police can hinder effective policing."

Sierra-Arévalo agrees but also provides a caution. "Respectful, positive interactions like those we tested can be a powerful tool to increase trust and should be encouraged in U.S. police departments. That said, community policing isn't going to end police brutality or address a continuing lack of police accountability; these are serious problems that demand concerted attention and their own solutions."


Rand, Peyton and Sierra-Arévalo are coauthors of "A field experiment on community policing and police legitimacy," which will be published by PNAS on Sept. 16, 2019.

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