(June 2013) Results of rigorous evaluations show that one of the most cost-effective ways to boost primary school attendance in western Kenya is to treat children for intestinal worms, a health-related intervention. That's the finding of researchers at the Massachusetts Institute of Technology (MIT) Jameel Poverty Action Lab (J-PAL).

Universal primary education for both boys and girls is one of the United Nations' Millennium Development Goals. A variety of programs have been launched—including cutting schools fees, distributing uniforms, serving free school meals—in attempts to remove the obstacles that keep children from attending school, explained Esther Duflo, an MIT economics professor and a founder and director of J-PAL.

When researchers used carefully controlled field trials to examine ways of increasing school attendance, they found that school-based de-worming in Kenya (requiring two treatments totaling $1 per child per year) had the biggest impact per dollar spent.

While intestinal parasites are not life threatening, they leave children anemic, lethargic, and listless; the researchers found that sick children miss school frequently.

The de-worming program was rolled out to schools in the western region over three years. The Kenyan schools that received the de-worming program the first year were chosen randomly from an alphabetized list. The incremental rollout and random way they chose which schools got the program first facilitated a rigorous evaluation of the de-worming program. This design allowed researchers to estimate the program's impact by comparing attendance among children in schools with the de-worming treatment to attendance among children in schools with no de-worming program.

This method of evaluation of anti-poverty programs is at the heart of the work of Duflo and J-PAL. The impact of social programs is examined by setting up treatment and nontreatment (control) groups from the outset, "the way we test drugs," she explained.

These types of evaluations require careful coordination among researchers and those implementing the anti-poverty interventions. But the results can build support for effective programs and better target the limited resources available to fight poverty, she argued.

"There are many ideas floating around, but the evidence is spotty on the most effective ways to have a social impact," she said. Based on J-PAL's evaluation results, the de-worming programs were expanded in Kenya and initiated in parts of Uganda and India.

But randomized evaluations are not a perfect; J-PAL staff have pointed out that this approach is not appropriate for evaluating every type of social intervention and the results are context-specific. For example, school-based de-worming in India had only about one-fifth the impact on school attendance as it did in Kenya, the J-PAL evaluations show. In settings where intestinal parasites are less widespread, such as parts of Latin America, other interventions are more appropriate.

A recent report on a project promoting improved household stoves underscores the strengths of this type of evaluation. Tested in a laboratory, these stoves cut indoor air pollution, improved health, required less fuel, and reduced greenhouse gas emissions. But researchers found different results when they examined the stoves in a community setting.

The field trial worked this way: Households in cities in India competed in a lottery for both the improved stoves and installation help from a well-respected nongovernmental organization. Duflo and her colleagues tracked the impact of the stoves for four years, examining households with and without the new stoves. They found some evidence of lower levels of smoke inhalation among household members with the new stoves in the first year, but "no effect over longer time horizons." Lung function and health did not improve, nor did fuel consumption decline.

"Households failed to use the stoves regularly or appropriately, did not make the necessary investments to maintain them properly, and use ultimately declined further over time" they reported.

The United States is a founding member of the Global Alliance for Clean Cookstoves and is supporting its "100 by '20" goal of 100 million homes adopting clean and efficient stoves and fuels by 2020. Writing in National Geographic NewsWatch, Duflo and her colleagues argued that their "one discouraging study should not set the world back in the effort to eradicate [indoor air pollution]." On the contrary, they write, "it should renew our enthusiasm to search, with open minds, for appropriate solutions."

In Duflo's view, this sort of rigorous evaluation in a real-world setting often challenges conventional wisdom but ensures that "policy decisions are based on scientific evidence." The lessons learned from research designed in this way can "inform future programs, increase the effectiveness of existing programs, and mobilize additional resources," she said.

Paola Scommegna is a senior writer/editor at the Population Reference Bureau.