Information provision, police beliefs and public trust: Experimental evidence from Colombia

Last registered on March 20, 2024

Pre-Trial

Trial Information

General Information

Title
Information provision, police beliefs and public trust: Experimental evidence from Colombia
RCT ID
AEARCTR-0008947
Initial registration date
March 02, 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
March 04, 2022, 9:12 AM EST

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

Last updated
March 20, 2024, 2:14 PM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Primary Investigator

Affiliation
Universidad EAFIT

Other Primary Investigator(s)

PI Affiliation
Interamerican Development Bank
PI Affiliation
National Police of Colombia

Additional Trial Information

Status
Completed
Start date
2022-03-21
End date
2022-07-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
The National Police of Colombia wants to raise their public trust and legitimacy by following procedural justice protocols in citizen-police day-to-day interactions. In our context, procedural justice refers to the idea of fairness in police decisions and interactions with citizens. We partnered with the Police to test an information campaign with police patrols across five Colombian cities: Barranquilla, Bucaramanga, Cali, Cartagena and Medellín---the largest Colombian cities excluding the capital Bogotá. The experimental sample consists of 351 police quadrants---a police patrolling area akin to a police beat. We randomly assigned quadrants to: (i) intensified interactions with citizens plus procedural justice instructions; (ii) intensified interactions with citizens plus procedural justice instructions, with the addition of an information campaign on procedural justice values; or (iii) neither. To randomize quadrants into treatment arms, we stratified by city, poverty level, and baseline public trust. We will measure impacts on police beliefs and public trust. Because patrolling areas are relatively large, we collect data on one street block within the quadrant, and ask police patrols to target it as a "pilot" block. We randomly sampled "pilot" street blocks within quadrants.

Note: We updated the abstract after the intervention finished, but not as an ex-post change. The intervention evolved after we registered the PAP, and this is a more accurate description of what the intervention effectively was.
External Link(s)

Registration Citation

Citation
Norza, Ervyn, Santiago Perez-Vincent and Santiago Tobon. 2024. "Information provision, police beliefs and public trust: Experimental evidence from Colombia." AEA RCT Registry. March 20. https://doi.org/10.1257/rct.8947-1.6
Sponsors & Partners

Sponsors

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Experimental Details

Interventions

Intervention(s)
We are testing two interventions: (i) intensified interactions with citizens plus procedural justice instructions; and (ii) intensified interactions with citizens plus procedural justice instructions, with the addition of an information campaign on procedural justice values. In our context, procedural justice refers to the idea of fairness in police decisions and interactions with citizens. Our units of analysis are police quadrants or patrolling areas, akin to police beats.

The first treatment arm consists of increasing police presence and the quality of interactions with citizens within the patrolling area. Police patrols will be instructed to intensify their presence and interactions, with specific instructions on the importance of police contact with citizens. Following the beginning of the intervention, patrols in this treatment arm will receive daily messages on procedural justice protocols, e.g., to be fair and to listen to citizens' complaints and questions.

The second treatment arm consists of exactly the same components as the first with the addition of an information campaign where police officers received daily reminders on the importance of procedural justice principles. These messages highlight, for instance, cordially greeting people before starting any dialogue or being empathetic with whoever they interact with.

Because patrolling areas are relatively large, we collect data on one street block within the quadrant, and ask police patrols to target it as a "pilot" block. We randomly sampled "pilot" street blocks within quadrants.

Note: We updated the intervention description after the intervention finished, but not as an ex-post change. The intervention evolved after we registered the PAP, and this is a more accurate description of what the intervention effectively was.
Intervention (Hidden)
Intervention Start Date
2022-03-21
Intervention End Date
2022-04-22

Primary Outcomes

Primary Outcomes (end points)
We have three main outcomes:

1. Public trust in the police
2. Demand for policing services
3. Police beliefs
Primary Outcomes (explanation)
We have three main outcomes:

1. Public trust in the police, measured through one single public trust question in the citizens survey

2. Demand for policing services, measured through a costly request (we asked residents whether they would support a new tax directed at funding the police)

3. Police beliefs, measured as their trust in citizens and their second-order beliefs on public trust

We expect the intervention will increase public trust and police beliefs.

Note: We updated the description of the police measures after the intervention finished, but not as an ex-post change. The instrument aimed to understand how effective procedural justice principles were by asking directly to officers how much they trust the public (a measure of reciprocity) and their second-order beliefs on public trust (the main aim of the intervention).

Secondary Outcomes

Secondary Outcomes (end points)
Our secondary outcomes are:

1. A first stage measure of police activity
2. Four indices to better understand the mechanisms that change public trust in the police: procedural justice, perceived effectiveness, perceived accountability and transparency, and convergence of values
Secondary Outcomes (explanation)
We will measure impacts on two secondary outcomes:

1. A first stage measure of police activity, measured as an additive index of a set of questions on police presence and behavior, asked in the citizens survey

2. Four indices to better understand the mechanisms that change public trust in the police, all measured in the citizens survey
2.1. Procedural justice, measured as an additive index of a set of questions on police behavior
2.2. Perceived effectiveness, measured as an additive index of a set of questions on perceived effectiveness of the police
2.3. Perceived accountability and transparency, measured as an additive index of a set of questions on perceived accountability, corruption and other transparency outcomes
2.4. Convergence of values, measured as an additive index of a set of questions on values and the idea of police legitimate use of force

We do not have priors on the directions of these secondary outcomes.

Experimental Design

Experimental Design
The study focuses on five Colombian cities: Barranquilla, Bucaramanga, Cali, Cartagena and Medellín---these are the largest Colombian cities excluding the capital Bogotá.

For our experimental sample, we randomly chose 351 quadrants out of the universe of police quadrants across the five cities---we excluded from the sampling frame only exceptional cases such as quadrants in a Caribbean island nearby Cartagena. From the experimental sample, quadrants will be assigned to each treatment arm using stratified randomization. Probability of assignment to each treatment arm is 33%.
Experimental Design Details
Randomization Method
Randomization was done in an office using a computer. We assigned treatment as follows:

First, we stratified by city. Within each city, we stratified by terciles of poverty scores using census data. Within each tercile of poverty score, we ranked quadrants based on the baseline public trust measure. Within each triplet in the ranking, we randomized quadrants. Probability of treatment assignment is 33% for all treatment arms.
Randomization Unit
Our units of analysis are police quadrants or patrolling areas, akin to police beats. These are discussed above.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
351 police quadrants.
Sample size: planned number of observations
About 2,100 surveys, 6 from each police quadrant. We will cluster observations by quadrant in our analysis.
Sample size (or number of clusters) by treatment arms
~351/3 police quadrants assigned to intensified interactions with citizens
~351/3 police quadrants assigned to intensified interactions with citizens plus procedural justice instructions
~351/3 police quadrants assigned to control
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
We used our baseline measure of public trust and ran 10,000 simulations to estimate the minimum detectable effects. For each randomization, we estimated treatment effects using a regression of a z-score of the public trust measure on indicators for both treatments, and fixed effects for city, income tercile and trust triplet. Our minimum detectable effects are of roughly 0.1 standard deviations for both treatments.
IRB

Institutional Review Boards (IRBs)

IRB Name
Universidad EAFIT
IRB Approval Date
2021-08-25
IRB Approval Number
N/A

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
Yes
Intervention Completion Date
April 30, 2022, 12:00 +00:00
Data Collection Complete
Yes
Data Collection Completion Date
July 31, 2022, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
351 quadrants
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
2,097 citizens, 2,123 police officers
Final Sample Size (or Number of Clusters) by Treatment Arms
115 quadrants in the more policing and better treatment arm; 116 in the COP more policing, better treatment and information campaign treatment arm; 114 in the control group
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials