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Alcohol and Self-Control: A Field Experiment in India
Last registered on April 17, 2018

Pre-Trial

Trial Information
General Information
Title
Alcohol and Self-Control: A Field Experiment in India
RCT ID
AEARCTR-0002898
Initial registration date
April 14, 2018
Last updated
April 17, 2018 2:33 PM EDT
Location(s)
Region
Primary Investigator
Affiliation
MIT Economics
Other Primary Investigator(s)
Additional Trial Information
Status
Completed
Start date
2014-05-01
End date
2014-09-30
Secondary IDs
Abstract
This study considers alcohol consumption among low-income workers in India. In a three-week field experiment, the majority of 229 cycle-rickshaw drivers were willing to forego substantial monetary payments in order to set incentives for themselves to remain sober, thus exhibiting demand for commitment to sobriety. Randomly receiving sobriety incentives significantly reduced daytime drinking while leaving overall drinking unchanged. I find no evidence of higher daytime sobriety significantly changing labor supply, productivity, or earnings. In contrast, increasing sobriety raised savings by 50 percent, an effect that does not appear to be solely explained by changes in income net of alcohol expenditures.
External Link(s)
Registration Citation
Citation
Schilbach, Frank. 2018. "Alcohol and Self-Control: A Field Experiment in India." AEA RCT Registry. April 17. https://doi.org/10.1257/rct.2898-1.0.
Former Citation
Schilbach, Frank. 2018. "Alcohol and Self-Control: A Field Experiment in India." AEA RCT Registry. April 17. https://www.socialscienceregistry.org/trials/2898/history/28406.
Experimental Details
Interventions
Intervention(s)
In a three-week field experiment with 229 men in Chennai, India, I offered a random subset of individuals financial incentives for sobriety, while a control group received unconditional payments of similar magnitude. The remaining individuals were offered the choice between sobriety incentives and unconditional payments. The randomized nature of the experiment allows me to investigate the impact of increased sobriety on labor market outcomes and savings behavior. To measure the impact of acute intoxication on intertemporal choices, all subjects were provided with a high-return savings opportunity. For a cross-randomized subset of study participants, the savings account was a commitment savings account, i.e. individuals could not withdraw their savings until the end of their participation in the study.

For a detailed description, see here: https://economics.mit.edu/files/14959
Intervention Start Date
2014-05-01
Intervention End Date
2014-09-30
Primary Outcomes
Primary Outcomes (end points)
(1) Individuals' savings at the study office; (2) Labor market outcomes (earnings, labor supply, productivity); (3) Demand for commitment to increase sobriety
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
229 cycle-rickshaw peddlers working in central Chennai were asked to visit a nearby study office every day for three weeks each. During these daily visits, individuals completed a breathalyzer test and a short survey on labor supply, earnings, and expenditure patterns of the previous day, and alcohol consumption both on the previous day and on the same day before coming to the study office. To study the impact of increased sobriety on savings behavior, we gave all subjects the opportunity to save money at the study office.

Participants were randomly assigned to various treatment groups with the following considerations. First, to create exogenous variation in sobriety, we offered a randomly-selected subsample of study participants financial incentives to visit the study office sober, while the remaining individuals were paid for coming to the study office regardless of their alcohol consumption. Second, to examine the interaction between sobriety incentives and commitment savings, a cross-randomized subset of individuals was provided with a commitment savings account, i.e. a savings account that did not allow them to withdraw their savings until the end of their participation in the study. Third, to identify self-control problems regarding alcohol, a randomly-selected subset of individuals was given the choice between incentives for sobriety and unconditional payments.

The experiment took place between April and September of 2014. 229 cycle-rickshaw peddlers working in central Chennai were asked to visit a nearby study office every day for three weeks each. During these daily visits, individuals completed a breathalyzer test and a short survey on labor supply, earnings, and expenditure patterns of the previous day, and alcohol consumption both on the previous day and on the same day before coming to the study office. To study the impact of increased sobriety on savings behavior, we gave all subjects the opportunity to save money at the study office.

Participants were randomly assigned to various treatment groups with the following considerations. First, to create exogenous variation in sobriety, we offered a randomly-selected subsample of study participants financial incentives to visit the study office sober, while the remaining individuals were paid for coming to the study office regardless of their alcohol consumption. Second, to examine the interaction between sobriety incentives and commitment savings, a cross-randomized subset of individuals was provided with a commitment savings account, i.e. a savings account that did not allow them to withdraw their savings until the end of their participation in the study. Third, to identify self-control problems regarding alcohol, a randomly-selected subset of individuals was given the choice between incentives for sobriety and unconditional payments.

(1) The Control Group was paid Rs. 90 ($1.50) per visit regardless of BAC on days 5 through 19. These participants simply continued with the payment schedule from Phase 1.

(2) The Incentive Group was given incentives to remain sober on days 5 through 19. These payments consisted of Rs. 60 ($1) for visiting the study office and an additional Rs. 60 if the individual was sober as measured by a score of zero on the breathalyzer test. Hence, the payment was Rs. 60 if they arrived at the office with a positive BAC and Rs. 120 if they arrived sober. Given the reported daily labor income of about Rs.\ 300 ($5) in the sample, individuals in the Incentive Group received relatively high-powered incentives for sobriety.

(3) The Choice Group was designed to elicit individuals' demand for sobriety incentives and simultaneously contribute to the estimation of the impact of increased sobriety. To familiarize individuals with the incentives, the Choice Group was given the same incentives as the Incentive Group in Phase 2 (days 5 to 7). Then, right before the start of Phase 3 (day 7) and Phase 4 (day 13), they were asked to choose for the subsequent six study days whether they preferred to continue receiving incentives or to receive unconditional payments ranging from Rs. 90 ($1.50) to Rs. 150 ($2.50), as described below.

For a detailed description of the experiment design, see here: https://economics.mit.edu/files/14959
Experimental Design Details
Randomization Method
In office by computer
Randomization Unit
Individual
Was the treatment clustered?
No
Experiment Characteristics
Sample size: planned number of clusters
229 individuals
Sample size: planned number of observations
229 individuals for 20 days each
Sample size (or number of clusters) by treatment arms
83 individuals in Control Group, 71 individuals in Incentive Group, 75 individuals in Choice Group
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
Harvard IRB
IRB Approval Date
2012-11-27
IRB Approval Number
F22612
Post-Trial
Post Trial Information
Study Withdrawal
Intervention
Is the intervention completed?
No
Is data collection complete?
Data Publication
Data Publication
Is public data available?
No
Program Files
Program Files
Reports and Papers
Preliminary Reports
Relevant Papers