How Do We Know What Works in the Fight Against Malaria?

How Do We Know What Works in the Fight Against Malaria?

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To observe World Malaria Day (Apr 25, 2023), IPA spoke via Zoom with Jessica Cohen, whose pioneering research helped shape current approaches to combating malaria.

Jessica Cohen still remembers the day she received a congratulatory email regarding her research on the impacts of the free distribution of insecticide-treated bed nets (ITNs) in Kenya.

Her research called into question the conventional wisdom that distributing ITNs free of charge was a mistake. Cohen and her co-author Pascaline Dupas upset that orthodoxy by demonstrating that charging even a small amount for ITNs reduced their uptake.

The congratulatory email stood out because it arrived nine years after the study was first published, in the Quarterly Journal of Economics.  The sender had seen Cohen’s research in Vox’s list of the “great social science” studies of the decade. The impacts of Cohen’s research are still being felt well after it was published.

“I felt very proud. The [Vox] article was very complimentary,” said Cohen, who was just two years out of her Ph.D. program when the paper was published. Today, she is the Bruce A. Beal, Robert L. Beal, and Alexander S. Beal Associate Professor of Global Health at Harvard University. But her paper continues to shape both her career and the global fight against malaria.

ITNs are a core intervention for malaria control. But how best to distribute them was not entirely settled when Cohen began her research. While most experts believed it was necessary to charge money for ITNs, she had a different idea, rooted in her experience in the early 2000s when she was working as a research assistant in Kenya.

“At that time, the rate of malaria was extremely high, especially in western Kenya. We decided to address it because it was a visible part of everyday life,” said Cohen, whose favorite memories in Kenya include riding boda-bodas — the local term for motorbike taxis — around the region to conduct her research.

Seeing the toll malaria was taking, Cohen decided to test whether the conventional wisdom was correct, or if there were better ways to encourage ITN use. Working with the IPA Kenya office — which helped her look for surveyors — she and Dupas designed a randomized evaluation that showed giving away ITNs for free dramatically increased their use in comparison to charging a nominal amount for them.

Shortly after the results came out, Population Services International (PSI) integrated the findings by providing free ITNs for many pregnant women throughout Africa. The British government also referred to the study in calling for the elimination of charges for health-related goods and services in low- and middle-income countries.

“Every once in a while, I look back on the work,” Cohen says. “I realize it has touched many people’s lives, the way we think of global health policy, and the way students learn about development economics.”

A photo of Jessica Cohen with a ITN as a background
Jessica Cohen talks about the groundbreaking study she co-authored with Pascaline Dupas on the free distribution of insecticide-treated nets, rather than charging a small fee for them. (Photo: Aude Guerucci & Jessica Cohen)


Looking Back, Looking Forward


Thirteen years after Cohen’s pathbreaking research was published, she applauds the global health community's focus on malaria. The latest World Malaria Report, published by the World Health Organization in December 2022, highlighted that malaria cases and deaths remained stable in 2021 despite the continued impact of COVID-19. Cohen also mentioned that the U.S. President’s Malaria Initiative — launched in 2005 by President George W. Bush — provides funding to combat malaria in Africa and has already saved millions of lives.

“It’s certainly not sufficient to tackle the level of the challenge but we should acknowledge that the global health community has really put a lot into malaria,“ she notes.

Today, both she and IPA continue contributing to research on malaria. Cohen is researching the impact of the wide-scale rapid diagnostic test for malaria in Sub-Saharan Africa. Meanwhile, IPA has studied the effectiveness of text messages in prompting people to complete the full course of their malaria treatment, finding that text message reminders increased adherence to the treatment regime by five percentage points over the comparison group.

Surveying the state of the global fight against malaria, Cohen says one of the tangible ways people can get involved is by supporting organizations that help prevent malaria.

“It’s really about taking action to get malaria under control so that people don’t miss work, school, and opportunities to be lifted out of poverty.”