Excessive Alcohol Consumption and Violent Brawls: A Randomized Controlled Trial with Bartenders in Bogotá, Colombia

Last registered on January 11, 2024
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Pre-Trial

Trial Information

General Information

Title
Excessive Alcohol Consumption and Violent Brawls: A Randomized Controlled Trial with Bartenders in Bogotá, Colombia
RCT ID
AEARCTR-0003845
Initial registration date
March 07, 2019

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 08, 2019, 3:55 PM EST

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

Last updated
January 11, 2024, 11:30 AM EST

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

Locations

Country
Colombia
Region
Bogotá

Primary Investigator

Name
Andres Ham
Affiliation
Universidad de los Andes
Contact Primary Investigator

Other Primary Investigator(s)

PI Name
Michael Weintraub
PI Affiliation
Universidad de los Andes
Contact Investigator
PI Name
Dario Maldonado
PI Affiliation
Universidad de los Andes
Contact Investigator
PI Name
Andres Felipe Camacho
PI Affiliation
Universidad de los Andes
Contact Investigator

Additional Trial Information

Status
Completed
Start date
2018-06-01
End date
2019-10-31
Keywords
Crime, Violence, & Conflict
Additional Keywords
alcohol consumption, violence, bartenders, brawls
JEL code(s)
C93, D90, I10, K42, O12
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Excessive alcohol consumption has been shown to instigate violence in public spaces, particularly in and around alcohol-serving establishments. Policies that ban or restrict alcohol have been shown to work but impose restrictions on the community and may be unenforceable. Less evidence exists regarding policies that raise awareness among bartenders and patrons of the adverse consequences of excessive alcohol consumption. In this study we evaluate an intervention conducted by the Bogotá mayor’s office and Colombia’s largest brewery to empower bartenders, provide didactic materials to bar patrons, and offer food and non-alcoholic drinks to bar patrons. The intervention has two primary objectives: i) reduce the negative consequences associated with the overconsumption of alcohol and ii) defuse conflicts between bartenders and patrons, and among patrons, that might escalate to violence within and around bars. Our unit of observation is the street segment, nested within police quadrants. We first randomize 221 police quadrants into treatment and control groups. Second, in the 109 treated quadrants, we randomly select eligible street segments with alcohol-serving establishments to receive the intervention. This design captures both direct effects of the intervention for street segments within treated police quadrants and potential spillover effects across police quadrants.
External Link(s)

Registration Citation

Citation
Ham, Andres et al. 2024. "Excessive Alcohol Consumption and Violent Brawls: A Randomized Controlled Trial with Bartenders in Bogotá, Colombia." AEA RCT Registry. January 11. https://doi.org/10.1257/rct.3845-1.2
Former Citation
Ham, Andres et al. 2024. "Excessive Alcohol Consumption and Violent Brawls: A Randomized Controlled Trial with Bartenders in Bogotá, Colombia." AEA RCT Registry. January 11. https://www.socialscienceregistry.org/trials/3845/history/207838
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
This randomized controlled trial studies the impact of an intervention directed at bartenders in four neighborhoods or localities in Bogotá, Colombia. The goal of the study is to determine whether alcohol-induced violent brawls can be reduced via a low-cost, scalable intervention undertaken through a public-private partnership between Bogot\'a's mayor's office, Colombia's largest brewery (Bavaria), and the team of researchers. The intervention has two primary objectives: i) reduce the negative consequences associated with the over-consumption of alcohol and ii) defuse conflicts between bartenders and patrons, and among patrons, that might escalate to violence within and around bars.
Intervention (Hidden)
The intervention aims to educate bartenders about what it means to be a "good" bartender, via in-person training and a take-home manual. We also provide incentives for bartenders to continually implement the lessons learned from this training and the manual. In so doing, we hope to better understand the role of bartenders in regulating clients' behavior, both within and beyond the sites where alcohol is sold and consumed. As previously mentioned, less work has been done on this front, and we believe that this is a fruitful way forward to empower a crucial community figure in spaces where violence frequently originates. We also target bar patrons via humorous yet pedagogically-useful materials that remind them of the need to drink water and eat food while consuming alcohol.
Intervention Start Date
2018-09-01
Intervention End Date
2018-11-30

Primary Outcomes

Primary Outcomes (end points)
Number of violent brawls
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Alcohol sales, water sales, food sales
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The randomization consists of two stages. Our universe consists of the four selected neighborhoods or localities in Bogotá. Next, within these localities, we identified eligible street segments: those with at least one violent brawl and one bar at a distance equal to or less than 100 meters. In the first stage of the randomization, we randomly selected treatment and control police quadrants. Bogotá is composed of 1,051 police quadrants in total. Selection of quadrants therefore occurred in two phases: first, quadrants with at least two pre-selected street segments (given the criteria described above) were chosen. Subsequently, using the Statistical, Criminal, Contravention and Operational Information System (SIEDCO) from the National Police, we discarded the most dangerous decile of quadrants within the four localities. Across the four localities there are 221 eligible police quadrants in total, 109 were selected into treatment and 112 into the control group.

The second stage of the assignment procedure randomly selects street segments within the 109 treated police quadrants to receive the intervention. Given budget constraints that restricted the number of treated bars to 270, we selected 218 street segments that contained approximately this number of alcohol-serving establishments.
Experimental Design Details
Randomization Method
Randomization done in office by a computer
Randomization Unit
First stage: Randomization took place at the police quadrant-level
Second stage: Within randomly selected treatment police quadrants, street segments were selected into treatment and control
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
221 Police Quadrants
2539 Street segments
Sample size: planned number of observations
152,340 street segments for 60 months (2539 street segments x 60 months)
Sample size (or number of clusters) by treatment arms
109 treated police quadrants and 112 control police quadrants
218 treated street segments within treated police quadrants and 2321 control street segments
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
MDE for number of violent brawls at police quadrant level: 0.30 SDs. (Mean=16.16, SD=12.06) MDE for number of violent brawls at street segment level: 0.27 SDs. (Mean=3.57, SD=3.19)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Institutional Review Board - Universidad de los Andes
IRB Approval Date
2019-03-07
IRB Approval Number
970
Analysis Plan

Analysis Plan Documents

Bavaria_PAP.pdf

MD5: 1bb6c74a0c44ead949d6ead7c6e81e79

SHA1: 142903165ad3e6257aa98391f275d020d8a569c9

Uploaded At: March 07, 2019

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
Yes
Intervention Completion Date
November 30, 2018, 12:00 +00:00
Data Collection Complete
Yes
Data Collection Completion Date
November 30, 2018, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Survey: 482 street segments
Administrative records: 5987 street segments
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
Survey: 578 bars in 482 street segments
Administrative data: 5987 street segments
Final Sample Size (or Number of Clusters) by Treatment Arms
Survey: 258 treated bars and 320 control bars Administrative data: 3029 pure control, 2730 indirectly treated, and 228 directly treated
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
No
Reports, Papers & Other Materials

Relevant Paper(s)

Abstract
This paper evaluates the randomized Good Drinks program in four localities of Bogotá, Colombia. The intervention encourages bartenders to adopt standardized practices that promote responsible behavior in terms of alcohol consumption with the goal of reducing alcohol-related violence and was implemented in cooperation with Colombia’s largest brewery and the city’s Secretariat of Security, Coexistence, and Justice. Tracing out the relationship between alcohol consumption and violence is useful because alcohol-related incidents often lead to more serious crimes. Our experimental design allows estimating direct and spillover effects on reported incidents within and around bars. Results show that bartenders in treatment locations sell more water and food, thus contributing to more responsible behavior by patrons. However, we find no direct or spillover effects of these changes in consumption on brawls five months after the program, but some improvement on other alcohol-related incidents. The experience of the Good Drinks program provides a better understanding of three aspects related to alcohol regulation and policy: (i) the role bartenders can play to curb excessive alcohol consumption and promote good behavior among customers, (ii) a practical experience of using less restrictive interventions for alcohol regulation, and (iii) the value of public-private partnerships.
Citation
Ham, A., Maldonado, D., Weintraub, M., Camacho, A. F., & Gualtero, D. (2022). Reducing Alcohol‐Related Violence with Bartenders: A Behavioral Field Experiment. Journal of Policy Analysis and Management, 41(3), 731-761.
URL
https://doi.org/10.1002/pam.22365

Reports & Other Materials