x

We are happy to announce that all trial registrations will now be issued DOIs (digital object identifiers). For more information, see here.
Free distribution or cost-sharing? Evidence from a randomized malaria prevention experiment.
Last registered on April 18, 2016

Pre-Trial

Trial Information
General Information
Title
Free distribution or cost-sharing? Evidence from a randomized malaria prevention experiment.
RCT ID
AEARCTR-0001167
Initial registration date
April 18, 2016
Last updated
April 18, 2016 4:49 PM EDT
Location(s)
Region
Primary Investigator
Affiliation
Stanford University
Other Primary Investigator(s)
PI Affiliation
School of Public Health, Harvard University
Additional Trial Information
Status
Completed
Start date
2007-02-01
End date
2007-08-31
Secondary IDs
Abstract
It is often argued that cost-sharing—charging a subsidized, positive price—for a health product is necessary to avoid wasting resources on those who will not use or do not need the product. We explore this argument through a field experiment in Kenya, in which we randomized the price at which prenatal clinics could sell long-lasting antimalarial insecticide-treated bed nets (ITNs) to pregnant women. We find no evidence that cost-sharing reduces wastage on those who will not use the product: women who received free ITNs are not less likely to use them than those who paid subsidized positive prices. We also find no evidence that costs haring induces selection of women who need the net more: those who pay higher prices appear no sicker than the average prenatal client in the area in terms of measured anemia (an important indicator of malaria). Cost-sharing does, however, considerably dampen demand. We find that uptake drops by sixty percentage points when the price of ITNs increases from zero to $0.60 (i.e., from 100% to 90% subsidy), a price still $0.15 below the price at which ITNs are currently sold to pregnant women in Kenya. We combine our estimates in a cost-effectiveness analysis of the impact of ITN prices on child mortality that incorporates both private and social returns to ITN usage. Overall, our results suggest that free distribution of ITNs could save many more lives than cost-sharing programs have achieved so far, and, given the large positive externality associated with widespread usage of ITNs, would likely do so at a lesser cost per life saved.
External Link(s)
Registration Citation
Citation
Cohen, Jessica and Pascaline Dupas. 2016. "Free distribution or cost-sharing? Evidence from a randomized malaria prevention experiment.." AEA RCT Registry. April 18. https://doi.org/10.1257/rct.1167-1.0.
Former Citation
Cohen, Jessica and Pascaline Dupas. 2016. "Free distribution or cost-sharing? Evidence from a randomized malaria prevention experiment.." AEA RCT Registry. April 18. https://www.socialscienceregistry.org/trials/1167/history/7730.
Sponsors & Partners

There are documents in this trial unavailable to the public. Use the button below to request access to this information.

Request Information
Experimental Details
Interventions
Intervention(s)
The trial looks to understand two aspects of ITN subsidies: whether a higher price ticket affects demand and whether a higher price paid leads to greater usage due to psychological sunk cost effects. The intervention is a two-stage pricing targeted to pregnant women seeking prenatal care in rural clinics.

First stage: Sample clinics were randomly assigned to one of five price groups: Sixteen health clinics were randomly selected to receive ITNs at a subsidized rate, with the discount varying between clinics from 90-100 percent of market price, and four comparison clinics were provided no ITN distribution program.

Second stage: Within a given clinic, a further discount is randomly offered to women who have already chosen to buy the net. This second stage is intended to allow separate estimation of the selection and sunk cost effects of price on usage discussed above.
Intervention Start Date
2007-03-01
Intervention End Date
2007-08-31
Primary Outcomes
Primary Outcomes (end points)
1) ITN uptake: how many participants choose to buy the ITN at offered price
2) ITN usage: self-reported and checked through unannounced home visits
3) Hemoglobin level (anemia status): Characteristic of clients selecting into buying ITN or not at any given price
Primary Outcomes (explanation)
1) ITN uptake: administrative records were kept by the clinic on ITN sales.

2) ITN usage: unannounced home visits were conducted with a randomly selected subsample of 246 women who had purchased ITNs. During the home visits, respondents were asked to show the net, whether they had started using it, and who was sleeping under it. Surveyors checked to see whether the net had been taken out of the packaging, whether it was hanging, and the condition of the net. During study rollout, clinic staff, enumerators or study participants were not informed that such visits would be conducted in order to ensure that usage was not unusually high due to Hawthorne effects.

3) Hb level: each clinic was visited three or four times on random days, and on those days enumerators surveyed all pregnant women who came for a prenatal visit. Women were asked basic background questions and whether they purchased a net, and their hemoglobin levels were recorded. In total, these measures were collected from 545 pregnant women.
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
Twenty rural clinics that provide prenatal services in the districts of Busia, Bungoma, Butere, and Mumias were chosen for the trial. Clinics were randomly assigned to either control or one of four different treatment arms. The treatment arms received a 90-100 percent subsidy on ITNs. Posters, announcing the price of the ITN were placed at the clinic and service providers were instructed to emphasize the importance of bed nets. Clinics were financially compensated for participation in the study.

For clinics where a positive price was charged, a second stage randomization took place. When a pregnant mother expressed interest to purchase a net at the price announced on the poster, she was offered a surprise lottery by picking up an envelope from a basket. The envelope contained the discount amount, if any. The lottery took place once a week, on varying weekdays, to avoid biasing the women’s decision on which day to visit the clinic.
Experimental Design Details
Randomization Method
To assign clinics to price groups, randomization was done in office by a computer
To assign surprise discount to women at the clinic if initial price was not 0, women drew a piece of paper from a bag.
Randomization Unit
Clinics.

However, there were three levels of randomization. First, clinics are randomized to be assigned to treatment and control groups. Within treatment groups, clinics are randomly assigned one of four price groups. Within a price group, patients entered a (unanticipated) lottery, once they agree to pay the price the clinic is charging for the ITN, to receive a discount ranging from 0% to a 100% (free).
Was the treatment clustered?
Yes
Experiment Characteristics
Sample size: planned number of clusters
20 clinics
Sample size: planned number of observations
Nets sales: 16 clinics; Baseline individual survey: 545 women; Follow up survey at home (purchased ITN): 246 women
Sample size (or number of clusters) by treatment arms
Control: 4 clinics
Treatment (0 Ksh,100% clinics): 5 clinics
Treatment (10 Ksh, 97.5% subsidy): 5 clinics
Treatment (20 Ksh, 95.0 % subsidy): 3 clinics
Treatment (40 Ksh, 90.0% subsidy): 3 clinics
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
Kenya Medical Research Insitute (KEMRI)
IRB Approval Date
2007-03-26
IRB Approval Number
KEMRI/RES/7/3/1
IRB Name
Innovations for Poverty Action Kenya
IRB Approval Date
2007-02-18
IRB Approval Number
20071
IRB Name
Dartmouth College
IRB Approval Date
2007-03-12
IRB Approval Number
20624
Post-Trial
Post Trial Information
Study Withdrawal
Intervention
Is the intervention completed?
Yes
Intervention Completion Date
August 31, 2007, 12:00 AM +00:00
Is data collection complete?
Yes
Data Collection Completion Date
August 31, 2007, 12:00 AM +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
16 clinics
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
Nets sales: 16 clinics; Individual Baseline survey: 545 women Follow up survey at home (purchased ITN): 246 women
Final Sample Size (or Number of Clusters) by Treatment Arms
Same as trial; no attrition of clinics. Control: 4 clinics Treatment (0 Ksh,100% clinics): 5 clinics Treatment (10 Ksh, 97.5% subsidy): 5 clinics Treatment (20 Ksh, 95.0 % subsidy): 3 clinics Treatment (40 Ksh, 90.0% subsidy): 3 clinics
Data Publication
Data Publication
Is public data available?
Yes
Program Files
Program Files
Yes
Reports and Papers
Preliminary Reports
Relevant Papers
Abstract
FREE DISTRIBUTION OR COST-SHARING? EVIDENCE FROM A RANDOMIZED MALARIA PREVENTION EXPERIMENT.

It is often argued that cost-sharing—charging a subsidized, positive price—for a health product is necessary to avoid wasting resources on those who will not use or do not need the product. We explore this argument through a field experiment in Kenya, in which we randomized the price at which prenatal clinics could sell long-lasting antimalarial insecticide-treated bed nets (ITNs) to pregnant women. We find no evidence that cost-sharing reduces wastage on those who will not use the product: women who received free ITNs are not less likely to use them than those who paid subsidized positive prices. We also find no evidence that costs haring induces selection of women who need the net more: those who pay higher prices appear no sicker than the average prenatal client in the area in terms of measured anemia (an important indicator of malaria). Cost-sharing does, however, considerably dampen demand. We find that uptake drops by sixty percentage points when the price of ITNs increases from zero to $0.60 (i.e., from 100% to 90% subsidy), a price still $0.15 below the price at which ITNs are currently sold to pregnant women in Kenya. We combine our estimates in a cost-effectiveness analysis of the impact of ITN prices on child mortality that incorporates both private and social returns to ITN usage. Overall, our results suggest that free distribution of ITNs could save many more lives than cost-sharing programs have achieved so far, and, given the large positive externality associated with widespread usage of ITNs, would likely do so at a lesser cost per life saved.
Citation
Cohen, Jessica, and Pascaline Dupas. 2010. "Free Distribution or Cost-Sharing? Evidence from a Randomized Malaria Prevention Experiment." The Quarterly Journal of Economics125(1): 1-45.