A Field Experiment on Door-to-Door Nonenforcement Community Policing Visits: Trust and Cooperation

Last registered on December 14, 2022


Trial Information

General Information

A Field Experiment on Door-to-Door Nonenforcement Community Policing Visits: Trust and Cooperation
Initial registration date
December 01, 2022

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
December 14, 2022, 2:08 PM EST

First published corresponds to when the trial was first made public on the Registry after being reviewed.


Primary Investigator

World Bank

Other Primary Investigator(s)

PI Affiliation
Boston University

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
We use a field experiment conducted with 980 households from San Luis Potosi, Mexico, to estimate whether the verbal and visual communication of police officers affects the actions, attitudes, and perceptions of the citizens with whom they interact. Randomly selected households received unannounced nonenforcement visits by police officers. Households were randomly assigned to receive one type of visual communication (tactical uniform versus proximity uniform) and one type of verbal communication (proximity message versus no message). The visits were implemented individually by police officers and lasted approximately 15 minutes. The essence of the visit was a nonenforcement interaction between a police officer and a citizen, in which the police officer conducted a structured survey with the citizen. The survey attempted to diagnose security problems faced by the community and general citizens’ attitudes and perceptions toward the police.
External Link(s)

Registration Citation

Canales, Rodrigo and Juan Santini. 2022. "A Field Experiment on Door-to-Door Nonenforcement Community Policing Visits: Trust and Cooperation." AEA RCT Registry. December 14. https://doi.org/10.1257/rct.10182-1.0
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Cooperation with the police (problem reporting), police trust, satisfaction with interaction
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
980 households were randomly assigned to receive with an equal probability the visit of an officer wearing a tactical uniform (the regular uniform of the San Luis Potosi police patrol unit) or a proximity uniform. The tactical uniform outfit included a handgun and bulletproof vest, and was color blue. The proximity uniform outfit did not include either a handgun or a bulletproof vest, and was color white. After introducing themselves, police officers asked households to participate in a survey to diagnose security-related problems in the community. Participation in the survey was voluntary and limited to one adult resident per household. Households that agreed to answer the survey were cross-randomized with an equal probability to receive a proximity message that states that the community is an active agent of security production in cooperation with the police. Four groups of households were created: i) tactical uniform proximity message; ii) tactical uniform no message; iii) proximity uniform proximity message; iv) proximity uniform no message.
Experimental Design Details
Randomization Method
Randomization by computer
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
Tactical uniform proximity message (n=235); tactical uniform no message (n=255); proximity uniform proximity message (n=243); proximity uniform no message (n=247)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Yale University Institutional Review Board
IRB Approval Date
Details not available
IRB Approval Number


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Intervention Completion Date
May 01, 2021, 12:00 +00:00
Data Collection Complete
Data Collection Completion Date
May 01, 2021, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
Final Sample Size (or Number of Clusters) by Treatment Arms
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials