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The Impact of Hotspot Policing and Municipal Services on Crime: Experimental Evidence from Bogota
Last registered on March 31, 2017

Pre-Trial

Trial Information
General Information
Title
The Impact of Hotspot Policing and Municipal Services on Crime: Experimental Evidence from Bogota
RCT ID
AEARCTR-0001156
Initial registration date
April 07, 2016
Last updated
March 31, 2017 4:49 PM EDT
Location(s)
Region
Primary Investigator
Affiliation
University of Chicago
Other Primary Investigator(s)
PI Affiliation
Columbia University
PI Affiliation
CAF
PI Affiliation
Universidad de Los Andes
Additional Trial Information
Status
Completed
Start date
2016-02-09
End date
2016-10-14
Secondary IDs
Abstract
Place-based policy interventions have been shown to effectively reduce crime, which exhibits a high level of spatial concentration. Two such strategies are hotspots policing, which focuses on targeting police and enforcement resources on specific streets, and broken windows, which focuses on cleaning up streets to stop criminal behavior. We partnered with the Bogota Police to test these two theories in 1,919 of the most crime-ridden street segments in the city. In a 2x2 factorial design, we assign street segments to receive hotspot policing, broken windows, both or neither. Our randomization strategy takes into account the spatial clustering of hotspots, which allows us to estimate direct treatment effects and indirect spillover effects.
External Link(s)
Registration Citation
Citation
Blattman, Christopher et al. 2017. "The Impact of Hotspot Policing and Municipal Services on Crime: Experimental Evidence from Bogota." AEA RCT Registry. March 31. https://doi.org/10.1257/rct.1156-6.0.
Former Citation
Blattman, Christopher et al. 2017. "The Impact of Hotspot Policing and Municipal Services on Crime: Experimental Evidence from Bogota." AEA RCT Registry. March 31. https://www.socialscienceregistry.org/trials/1156/history/15644.
Sponsors & Partners

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Experimental Details
Interventions
Intervention(s)
We are testing two interventions: hotspots policing and the provision of municipal services, or a broken windows treatment, in a 2x2 factorial design.

The hotspot policing intervention consists of increasing the dosage of police patrolling time from about 55 minutes per day per hotspot street segment (defined in section [sec:Design-randomization]) to 90, divided in six entries of 15 minutes each. This entry time is not arbitrary and is rather based on previous evidence from Telep et al. (2014), which finds decreasing returns on crime control after 15 minutes of police presence. Moreover, police patrols will be given specific instructions on how to distribute entries during the day. Hotspots located nearby bars and night clubs will have three entries during the day and three during the night. Other hotspots will have five entries during the day and one during the night. For hotspots in the control group, police will not receive any special instructions and will be free to patrol as they see fit. Activities while patrolling are standard, i.e. criminal record checks, door-to-door visits to the community, arrests, drug seizures, etc. Also, when necessary, police patrols will focus on problem-oriented policing strategies with support from different police branches as youth and juvenile, or counter narcotics specialized agents. The intervention began on February 9, 2016 and will continue for six months. The research team did not see any outcome data before this PAP was registered.

The broken windows intervention consists of sending a municipal team to selected hotspots to clean up streets in order to promote more informal social control by residents. The municipal team will be charged with repairing street lights, cleaning non-artistic graffiti, and collecting garbage every few weeks. The intervention began on April 6, 2016 (at the halfway mark of the hotspot policing intervention) and will continue until the end of the hotspots policing intervention. we batched units into two groups. The intervention will include an evaluation of compliance, which will help decide if we move on to the second batch or intensify the first batch.
Intervention Start Date
2016-02-09
Intervention End Date
2016-10-14
Primary Outcomes
Primary Outcomes (end points)
See section 4 in PAP.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
See section 2.3 in PAP.
Experimental Design Details
Randomization Method
STATA code
Randomization Unit
Street segment level
Was the treatment clustered?
No
Experiment Characteristics
Sample size: planned number of clusters
none
Sample size: planned number of observations
1,919 segments
Sample size (or number of clusters) by treatment arms
756 receive hotspot policing
415 receive broken windows
See table 4 in PAP for distribution of all 16 experimental conditions
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
See section 6.7 in PAP.
Supporting Documents and Materials

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IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
Columbia University
IRB Approval Date
2016-02-25
IRB Approval Number
IRB-AAAQ7568
IRB Name
Innovations for Poverty Action
IRB Approval Date
2016-04-01
IRB Approval Number
13991
IRB Name
Universidad de Los Andes
IRB Approval Date
2016-02-09
IRB Approval Number
n/a
Analysis Plan
Analysis Plan Documents
Pre-Analysis Plan - Final

MD5: 9cb4d96954b56a9c8aa17bc8a4863951

SHA1: fe70bebad28fee5cf506a35dc151f95aaba6e5fc

Uploaded At: August 30, 2016

Post-Trial
Post Trial Information
Study Withdrawal
Intervention
Is the intervention completed?
Yes
Intervention Completion Date
October 14, 2016, 12:00 AM +00:00
Is data collection complete?
Yes
Data Collection Completion Date
October 14, 2016, 12:00 AM +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
1,919 hotspots
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
1,919 hotspots
Final Sample Size (or Number of Clusters) by Treatment Arms
756 treated by hotspot policing, 201 treated by municipal services (75 with both)
Data Publication
Data Publication
Is public data available?
No
Program Files
Program Files
No
Reports and Papers
Preliminary Reports
Relevant Papers