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Retailer Experiment - Intervention to fight anemia and improve well-being in a very low income setting
Last registered on October 28, 2013


Trial Information
General Information
Retailer Experiment - Intervention to fight anemia and improve well-being in a very low income setting
Initial registration date
Not yet registered
Last updated
October 28, 2013 6:53 AM EDT
Primary Investigator
CESS Nuffield - FLAME University
Other Primary Investigator(s)
PI Affiliation
PI Affiliation
Additional Trial Information
On going
Start date
End date
Secondary IDs
Iron deficiency anemia (IDA) has been linked to low productivity in adults, slowing of cognitive and physical growth among children and, in the elderly, increased risk of cognitive impairment and physical disability, as well as decreased muscle strength.

Distributing iron supplements appears to be an impractical policy in resource-poor settings where the public health systems do not have the capacity to maintain a large-scale distribution system. Iron supplementation of foods is therefore an attractive alternative: it requires no additional effort on the part of the consumer, and can be done relatively cheaply in centralized locations. While NIN's Iron (and Iodine) Fortified Salt (DFS) has been studied extensively by the National Institute of Nutrition (Hyderabad) and others for safety and efficacy in humans, willingness to pay for this new technology has not been established.

In this experiment, we offer a limited, short-term discount off DFS wholesale purchases to private shops in randomly selected villages in order to study competition among retailers and the impact on DFS sales.
External Link(s)
Registration Citation
Banerjee, Abhijit, Sharon Barnhardt and Esther Duflo. 2013. "Retailer Experiment - Intervention to fight anemia and improve well-being in a very low income setting." AEA RCT Registry. October 28. https://doi.org/10.1257/rct.89-1.0.
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Experimental Details
The experiment's stockist visits the shops in the experiment and offers a discount of Rs. 3 per one kg packet of salt purchased by the store. This offer is made during a visit for taking orders. The salt is delivered the following day and paid for by the store at that time. Stores that run out of DFS are eligible for the discount until the next round of stocking starts by calling the stockist and asking for a delivery. This is the usual method of getting a special (off-cycle) distribution.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Change in retail sales of DFS following the temporary wholesale discount- quantity and price
Primary Outcomes (explanation)
1. The change in the amount of DFS the private store purchases during the incentive round, compared to previous rounds of restocking.
2. The change in the amount of DFS the private store purchases in the restocking round after the incentive round.
3. The price charged to households.
4. Household take-up of DFS.
Measurement of these outcomes will be done through a brief, door-to-door household survey and store survey.
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
In a larger experiment, we are making DFS available for stores to stock and sell in 200 villages. In this store experiment, we limit our sample to the 189 villages that have at least two private shops. We randomly assign those villages to one of three conditions:

1. All private stores in the village will be offered a limited time discount on the purchase of DFS.
2. One randomly selected private store in the village will be offered the same discount.
3. No private stores in the village will be offered the discount (control group).
Experimental Design Details
Randomization Method
Randomization done in office by a computer.
Randomization Unit
189 Villages
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
189 villages
Sample size: planned number of observations
189 villages, 1614 private shops, 2835 households
Sample size (or number of clusters) by treatment arms
63 villages in each arm:
- all private shops given discount
- one private shop given discount
- zero private shops given discount
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
IRB Approval Date
IRB Approval Number
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)