Kenya Insecticide-Treated Bednet Distribution
IPA / Harvard / MIT · Western Kenya · 2003
Summary
This study addressed a fundamental debate in development economics: does charging even a small price for a health product increase recipients' commitment to using it (the 'sunk cost' hypothesis)? The answer for bednets was no. Free recipients used their nets at the same rate as those who paid. Price was purely a take-up barrier, not a commitment device. The finding helped shift global malaria prevention policy toward free mass distribution of long-lasting insecticide-treated nets, a policy credited with saving millions of lives. Pascaline Dupas and others replicated the finding across multiple health products.
Research question
"Does subsidizing or freely distributing insecticide-treated bednets (ITNs) increase usage compared to charging market prices?"
Methodology
Intervention
Vouchers for highly subsidized nets vs. free nets vs. near-market-price nets at prenatal clinics
Assignment
Randomized controlled trial (individual)
Sample size
~1,000 pregnant women at prenatal clinics
Primary outcome
Bednet take-up; bednet usage; child malaria incidence
Effect estimate
Free distribution: 99% take-up; subsidized (10 cents): 75%; near-market price: 25%; usage among recipients did not differ significantly by price paid; no 'free makes you value it less' effect found
Decision
Evidence influenced WHO recommendation for free mass distribution; LLIN free distribution now standard globally
Result
Positive
Free distribution: 99% take-up; subsidized (10 cents): 75%; near-market price: 25%; usage among recipients did not differ significantly by price paid; no 'free makes you value it less' effect found
Evidence strength
Strong
Randomized trial, replicated across multiple sites or studies.
Replication status
Replicated
Institution
IPA / Harvard / MIT
Location
Western Kenya
Year
2003
Policy area
International Development
Mechanism
Price signal