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A Field Study of Donations at Supermarket Cash Registers
Last registered on June 30, 2016

Pre-Trial

Trial Information
General Information
Title
A Field Study of Donations at Supermarket Cash Registers
RCT ID
AEARCTR-0001398
Initial registration date
June 30, 2016
Last updated
June 30, 2016 12:57 PM EDT
Location(s)
Primary Investigator
Affiliation
University of Pittsburgh
Other Primary Investigator(s)
PI Affiliation
Pontificia Universidad Católica de Chile
PI Affiliation
Harvard Business School
Additional Trial Information
Status
In development
Start date
2016-06-07
End date
2016-10-31
Secondary IDs
FONDECYT INI 11140101
Abstract
Since 1996, a leading supermarket chain store in Chile has allowed its costumers to donate to a prominent local non-profit organization as they pay for their purchases at the cash register. The two organizations will soon conduct a transparency campaign informing costumers that (1) 100% of the donations made at the supermarket cash registers go to the organization, (2) the supermarket cannot legally get a tax break from the donations it collects at its registers, and (3) donations can be made with any payment method. In collaboration with the charity and the supermarket chain, we selected a group of approximately 60 stores to implement an RCT to evaluate the impact of this campaign on donation behavior. To further investigate the effect of information on the reasons costumers give for donating or not at the cashiers, we collect survey data on beliefs about the destiny of their donations before and during the intervention.
External Link(s)
Registration Citation
Citation
Keenan, Elizabeth, David Klinowski and Rosario Macera. 2016. "A Field Study of Donations at Supermarket Cash Registers." AEA RCT Registry. June 30. https://doi.org/10.1257/rct.1398-1.0.
Former Citation
Keenan, Elizabeth, David Klinowski and Rosario Macera. 2016. "A Field Study of Donations at Supermarket Cash Registers." AEA RCT Registry. June 30. https://www.socialscienceregistry.org/trials/1398/history/9175.
Experimental Details
Interventions
Intervention(s)
Intervention Start Date
2016-07-01
Intervention End Date
2016-07-15
Primary Outcomes
Primary Outcomes (end points)
From data collected by the supermarket:
1. Daily total donations by store (before, during and after the intervention).
2. Daily data at the store level (number of costumers and purchases)
From data collected from surveys (as reported by the customers):
1. Asking frequency by cashiers
2. Donation behavior (extensive margin)
3. Reasons for donating
4. Reasons for not donating
5. Beliefs about supermarket keeping part of donation
6. Perceptions about supermarket
7. Perceptions about charitable organization
8. Measures on a 5-pt scale of guilt (self-reported), pressure (self-reported), altruism (self-reported), principle of care (self-reported) and image concern (actual behavior measured by wearing sticker, see below)
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
Half of the sample of stores we study are randomly selected to receive the campaign, and the other half do not receive it at the time of the study. We measure the impact of the campaign by surveying costumers as they exit the store, for both treatment and control stores. We previously collect baseline data from similar surveys for a subset of all stores in our sample.
Experimental Design Details
In July 2016 the supermarket and the charity will be launching a transparency campaign. The campaign consists of placing signs at the stores and distributing flyers to costumers clarifying that (1) 100% of the donations made at the supermarket cash registers go to the charity, (2) the supermarket cannot legally get a tax break from the donations it collects at its registers, and (3) donations can be made with any payment method. In collaboration with the charity and the supermarket, we selected a subgroup of 40 stores within the Metropolitan area in Santiago de Chile to evaluate the efficacy of the campaign at increasing donations and to explore the underlying mechanisms for any effect. We selected the 40 stores randomly from the total of approximately 110 stores in the region. The randomization was stratified at the type of store (3 types as defined by the supermarket chain company) and, within each type, at whether they were below or above the median donation rate. In June 2016 we conducted the first wave of the survey to obtain baseline data. We could not visit 4 of the 40 stores at this wave because the 4 stores were either closed or prohibitively distant for the surveyors to get to them. To conduct the survey we approached costumers inside the store (as they finished their payment) or as they exited the store (if we lacked permission from the store manager to go inside). To ensure anonymity and confidentiality, the surveys were answered on iPads that were handed to costumers who agreed to participate. No personal information was collected or requested. To avoid demand effects, the surveyors wore T-shirts from a local university, and an association with the charity or the supermarket was never mentioned. At the end of the survey, respondents were offered a sticker with the text "I helped" and the University logo. This first wave lasted 7 days. We plan to conduct the second wave in July 2016, when the campaign is expected to start. Before conducting the first wave, we selected at random (stratified as described before) half of the 40 first-wave stores to receive the campaign, and the other half to not receive it at the time of the study. At the request of the charity (request coming after the first wave finished), we have increased the number of stores that will participate in the second wave to 60. The additional stores were randomly selected from the total population; half of them were randomly assigned to receive the campaign, and the other half to not receive it at the time of the study, using the same stratification as before. The surveys for this second wave will be conducted as before, and the wave is expected to last 5 to 15 days depending on logistics. Finally, pending availability of resources, we plan to conduct a follow-up third wave on the 60 second-wave stores. The surveys for this second wave will be conducted as before, and the wave is expected to last 5 to 15 days depending on logistics.
Randomization Method
Randomization done in office by a computer.
Randomization Unit
The unit of randomization is the store.
Was the treatment clustered?
Yes
Experiment Characteristics
Sample size: planned number of clusters
40 stores for first wave (baseline), 60 stores for second wave.
Sample size: planned number of observations
1200 costumers for first wave, 2000 costumers for second wave.
Sample size (or number of clusters) by treatment arms
30 stores control, 30 stores campaign.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
Pontificia Universidad Católica de Chile
IRB Approval Date
2016-05-04
IRB Approval Number
160428011
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