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Messaging and Tangible Donations in a Supermarket Setting
Last registered on October 29, 2019


Trial Information
General Information
Messaging and Tangible Donations in a Supermarket Setting
Initial registration date
October 29, 2019
Last updated
October 29, 2019 2:43 PM EDT
Primary Investigator
University of East Anglia
Other Primary Investigator(s)
Additional Trial Information
On going
Start date
End date
Secondary IDs
This research aims to use a field experiment to investigate whether reminders to donate at the time of purchase can affect the number and type of in-kind charitable donations made to a local food provision organisation, and to see how these effects change over time. The signs use messaging which makes the local aspect of the recipients salient.
A commonly cited reason for not donating to the FoodBank is that visitors to a supermarket forget to make a donation until they have already reached the end of their shopping and paid for their items. In conjunction with key items not being donated, this leaves great room for improvement in the type and level of donations made to the FoodBank. FoodBanks receive around half of their total donations from donation points in supermarkets, so getting this element of their strategy right would have large effects on their overall stock levels.
The use of shelf level signs to remind individuals to purchase an item for donation during their shop, and highlight which items are most needed, would appear to solve these two barriers to donation. These have been trialled in some stores in the UK, but as of yet the effect of these signs on donation rates has not been investigated.
External Link(s)
Registration Citation
Almond, Rhosyn . 2019. "Messaging and Tangible Donations in a Supermarket Setting." AEA RCT Registry. October 29. https://doi.org/10.1257/rct.4894-1.0.
Experimental Details
There are two treatments in this intervention. They take place in 18 local grocery stores which collect donations for the local FoodBank. 6 are assigned to each arm, and 6 to the baseline control group. The treatments involve highlighting which items are most needed by the Norwich FoodBank with the use of shelf level labelling and posters. The resulting donations made in store are measured weekly for the 10 week duration of the intervention. The percentage of donations of the highlighted item types will be compared between stores to find the effect of the treatment.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
The percentage of 'treated' or "most-needed" items that are donated each week. The overall donation level (in weight, £, and number of items).
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
This experiment is a randomised control experiment. It is unblinded, however the subjects will not know that they are in an experiment as they are likely to only shop at one of the branches. There are 2 Treatments and one control group. It is a between groups design - each store is exposed to only one treatment for the duration of the experiment.

Experimental Design Details
Randomization Method
Randomisation is done through the use of a Python code with a set seed and is replicable.

Block randomisation was used on three variables. The three variables were: local income (a proxy measure for this is used: the percentage of free school meals recipients in the nearest primary or infant school); store characteristics (the presence of a Post Office or a Subway inside the store - this could affect footfall); accessibility of donation point (whether the donation basket was located after the checkout, or requires a customer to double back on their journey out of the store). There are guiding hypotheses for these three variables leading to the use of them in the blocking randomisation.
Randomization Unit
Individual Store
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
Individual Stores
Sample size: planned number of observations
900 "most needed item" weekly totals. (18 stores, 5 items per store, for 10 weeks)
Sample size (or number of clusters) by treatment arms
6 grocery stores per arm, 3 arms. 1 arm control, 2 arms of treatments.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
School of Economics Research Ethics Committee, University of East Anglia
IRB Approval Date
IRB Approval Number
Analysis Plan

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Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)