The challenge
Intestinal worms made schoolchildren sick and kept them out of class.
The case
Starting in 1998, the NGO ICS Africa phased in mass deworming treatment at schools in western Kenya, randomly choosing which schools started first. Children in treated schools missed about a quarter less school, and because worms spread between children, untreated children nearby benefited too. Follow-ups two decades later found that those who had been treated as children had higher earnings and consumption. Kenya later scaled school deworming nationally. J-PAL reports that school participation among treated pupils rose by at least 9.3 percentage points in the first year compared with the comparison group.
Why it worked
A very cheap health intervention had lasting educational and economic effects. The original findings were fiercely debated by other researchers, a reminder that even influential studies need replication and scrutiny.
Sources
- J-PAL. Primary School Deworming in Kenya (evaluation summary of Miguel & Kremer 2004).
- Miguel, E., & Kremer, M. (2004). Worms: Identifying impacts on education and health in the presence of treatment externalities. Econometrica.
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