Michael Kremer’s Kenyan experiment helped bring free deworming to schoolchildren

Person: Michael Kremer
Lived: b. 1964
Field: Development economics
From: American

The story

Michael Kremer was born in New York in 1964 to parents who were both children of Jewish immigrants from Poland. After graduating from Harvard in 1985 he spent a year teaching at a secondary school in western Kenya, an experience that led him to devote his career to the economics of poverty.

In the late 1990s a friend from those Kenyan years was planning a programme to help primary school children, including pills against intestinal worms, which infect hundreds of millions of children in poor countries and can cause anaemia, malnutrition and fatigue. Kremer suggested rolling the programme out to schools in a random order, so that schools treated first could be fairly compared with schools treated later, the same logic as a clinical trial. Treatment began in 1998.

The results, published by Kremer and his student Edward Miguel in 2004, showed large effects on children’s health and schooling, including a 25 percent fall in school absenteeism. A long-term follow-up published in 2021 found that people who had received two to three extra years of deworming as children had consumer spending about 14 percent higher as adults. Another of Kremer’s experiments showed how much price matters: 75 percent of parents gave their children deworming pills when they were free, but only 18 percent when they cost less than a dollar.

The Royal Swedish Academy of Sciences noted that, in line with these findings, the World Health Organization recommends that deworming medicine be distributed free to schoolchildren in areas where infection is common, a group of more than 800 million children. Kremer co-founded the Deworm the World Initiative, now run by the nonprofit Evidence Action, which helps governments in countries such as India, Kenya, Nigeria and Pakistan run school-based deworming. It has supported more than 1.8 billion treatments since 2014, at a cost GiveWell estimates at well under a dollar per child.

Researchers continue to debate how large the long-term benefits are. GiveWell considers the evidence that the pills reduce worm infections strong and the evidence on later life outcomes weaker, but rated Deworm the World a top charity from 2013 to 2022 because the potential benefits are large and the cost tiny.

Why it matters

School deworming programmes that Kremer’s research helped launch treat hundreds of millions of children a year for a few cents each, improving their health and helping them stay in school.

About Michael Kremer

Economist who brought field experiments to the fight against poverty; his school deworming and vaccine purchase work reached hundreds of millions of children. Nobel Prize 2019.

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Michael Kremer

b. 1964 · Development economics

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