GiveWell Conversations

Stephan Guyenet, senior researcher with a background in biochemistry and neuroscience, helps untangle the evidence around vitamin A supplementation. They discuss why old randomized trials showed big mortality reductions. They cover challenges applying those findings today, novel analyses on dosing and disease-specific effects, and how updated estimates shaped GiveWell’s funding decisions.

Julie Faller, GiveWell Program Director who oversees research and grantmaking, walks through value-of-information grants that shape future funding. She describes pilots testing GiveDirectly cash-transfer variations, a footbridge-plus-cash feasibility trial, a large ORS distribution trial in Nigeria, and household surveys on fortified flour consumption. Short timelines and selection processes for pilots are also discussed.

Erin Crossett, Senior Program Officer at GiveWell who leads the water team and researches evidence-based program evaluation, discusses independent surveys that found Dispensers for Safe Water reached far fewer people than routine monitoring suggested. They cover how dispensers work, why monitoring overstated usage, the decision not to renew large-scale funding, and plans for verification and future pilots.

Natalie Crispin, lead of GiveWell’s vaccination work with deep experience in vaccine research and grantmaking. She discusses shifting from funding proven program types to targeting local bottlenecks that prevent vaccinations. They cover targeted outreach in low-coverage areas, data-driven planning and measurement, cold-chain and supply risks, and the tradeoffs between piloting experiments and delivering immediate impact.

Seasonal malaria chemoprevention (SMC)—a program that provides preventive antimalarial medication to young children during the months when malaria is mostly likely to be transmitted—is one of the most cost-effective programs GiveWell has identified. Malaria Consortium’s SMC program has been one of our Top Charities since 2016, and we’ve recommended more than $500 million in grants to the program.Most of our funding to date has supported programs in West Africa, where strong evidence gives us confidence in the effectiveness of the drug combination used. In eastern and southern Africa, malaria chemoprevention programs could potentially help many more children, but we have substantial uncertainties about drug effectiveness in that region.In this episode, GiveWell CEO and co-founder Elie Hassenfeld speaks with Senior Researcher John Macke about the CHAMP trial, a randomized controlled trial of chemoprevention drugs we’re supporting in Malawi, and how it could shape our malaria grantmaking.This research is one example of how GiveWell is building for the future: investing in research now that could substantially expand our ability to direct funding cost-effectively in the years ahead.Elie and John discuss:Why eastern and southern Africa present different challenges: One of the drugs used in seasonal chemoprevention shows widespread resistance in the region, and existing trial evidence about the effectiveness of chemoprevention there has limitations. While we’ve supported SMC in parts of Uganda and Mozambique, we’ve been cautious about scaling up without stronger evidence on which drug combinations work and whether using certain drugs could increase resistance.What this trial will tell us: The trial will test three drugs alone and in different combinations across roughly 7,000 children in Malawi, making it the largest individually randomized trial of chemoprevention drugs ever conducted. We’ll learn about the efficacy of the two drugs currently used in SMC, as well as an additional drug that had previously shown resistance but might now be effective again. The trial will look at the effect of the drugs on both malaria infections and hospitalizations caused by malaria.How the results could affect our grantmaking: Depending on what we learn, this trial could open up more than $100 million in cost-effective funding opportunities for chemoprevention programs each year in eastern and southern Africa. The trial results will also provide a knowledge base for other funders and implementers to improve the cost-effectiveness of malaria programming. We expect initial results in mid- to late 2027, with the potential for resulting grants to provide medication to children in 2028-2029.Visit our Top Charities Fund and All Grants Fund pages to learn more about how you can support this work, and listen or subscribe to our podcast for our latest updates.This episode was recorded on January 22, 2026 and represents our best understanding at that time.

Julie Faller, Senior Program Officer at GiveWell, explains how new research and grantmaking methods are uncovering cost-effective interventions. She discusses running RFPs to find unfamiliar implementers, funding a portfolio of inline chlorination pilots across African contexts, vaccine outreach trials to boost coverage, and varied research and cash-transfer program experiments.

GiveWell has built its reputation on rigorous research—analyzing randomized controlled trials, building cost-effectiveness models, and reviewing monitoring data to identify cost‑effective ways to save and improve lives.In an effort to supplement this desk research and make better decisions, we’ve been working to gather more information directly from the people who live and work in the countries where we fund programs.In this episode, GiveWell CEO and co-founder Elie Hassenfeld speaks with Principal Researcher Alex Cohen about GiveWell’s work to gather local insights to check our assumptions and figure out what we might be missing.Elie and Alex discuss:Testing key hypotheses about the data GiveWell relies on: We’re working to improve the inputs in our decision making. This includes checks on coverage data, more information about how programs work in practice, and assessing whether estimated program effects are plausible. These efforts have already identified discrepancies between coverage surveys and other areas for improvement.Addressing the limitations of global health data: GiveWell depends on credible data for its research, yet global health and development data is quite limited. For example, basic measurements like child mortality rates rely on household surveys conducted only every five years. We’re employing multiple approaches to address these limits: funding independent survey firms; conducting site visits; hiring local consultants; and strengthening networks with government officials, implementing organizations, and other funders.Balancing the trade-offs between local work and desk research: Desk research will continue to make up the vast majority of our work. We believe that complementing that research with additional information we gather from local sources could meaningfully improve our grantmaking. We expect to dedicate around 5% of our research team’s time and around 1% of our total grantmaking to these efforts, which we believe will have an outsized impact.By prioritizing efforts to learn from people in the places where we fund programs, we hope to better understand how programs are being implemented, identify bottlenecks, and more. We believe that incorporating this information will improve our decision-making and our work to help people as much as we can. It provides checks on our primary models, increases confidence in our conclusions, and could highlight where we might be missing something important.Visit our All Grants Fund page to learn more about how you can support this work, and listen or subscribe to our podcast for our latest updates.This episode was recorded on December 23, 2025 and represents our best understanding at that time.

Teryn Maddox, Director of Research at GiveWell, discusses the significant funding disruptions in global health during 2025. She shares insights on GiveWell's adaptive response strategies, balancing urgency with rigorous research. Teryn highlights the importance of pre-existing partnerships in malaria funding and explains the shift in focus towards HIV due to new treatment innovations. The conversation also covers lessons learned from navigating uncertainty, the evolving aid structure, and plans for future grantmaking in 2026.

On Thursday, December 4, 2025, GiveWell hosted a live webinar titled “Growing Needs, Shrinking Aid: Cost-Effective Action in a Year of Funding Cuts.” Major cuts to foreign aid this year created deep uncertainty for global health programs. In this live-recorded discussion, co-founder and CEO Elie Hassenfeld moderates a panel of GiveWell researchers to discuss the effects of these cuts and how GiveWell is leveraging its nearly two decades of experience in cost-effectiveness research and analysis to identify opportunities for exceptional donor impact.The panelists—Rosie Bettle (Program Officer, Malaria), Alex Bowles (Program Officer, Malaria), Meika Ball (Senior Research Associate, New Areas), and Dilhan Perera (Senior Research Associate, New Areas)—answered questions selected live by attendees and shared their insights. They discussed the challenges of understanding the cuts’ impacts, how GiveWell adapted its grantmaking approach to fund time-sensitive opportunities, the trade-offs the research team had to make in the face of uncertainty, and new areas that might have cost-effective funding gaps. The conversation explores what the research team has learned so far, along with their predictions and uncertainties about the future. We expect needs to continue growing in the years ahead as the effects of current and future cuts accumulate. In this context of growing need, it’s increasingly important that resources are used as effectively as possible. Check out this blog post to learn more about our response to this year’s aid cuts, visit the All Grants Fund page to learn more about how you can support this work, and listen or subscribe to our podcast for our latest updates.This episode was recorded on December 4, 2025 and represents our best understanding at that time.

This episode follows up on the November 26, 2025 episode of Planet Money, “Saving lives with fewer dollars,” which covered GiveWell’s evaluation of a grant to the Alliance for International Medical Action (ALIMA) to maintain primary healthcare, hospital services, and malnutrition treatment in two subdistricts of North Cameroon following unexpected aid cuts earlier this year. We recommend listening to the Planet Money episode first, as it provides important context. ***Significant changes to foreign aid this year created challenges for implementing organizations—and for funders evaluating which programs to support with limited resources. The Planet Money team followed along as we assessed the effects of the cuts in real time, focusing on our evaluation of a potential grant to ALIMA to maintain nutrition and primary healthcare services in Cameroon. Following the announcement of the US government’s stop-work order and funding freeze in January, we created a rapid response research team and began assessing opportunities we thought were potentially highly cost effective. In March, we launched an investigation of the $1.9 million ALIMA grant, which we funded in June based on the team’s findings.In this episode, GiveWell CEO and co-founder Elie Hassenfeld dives deeper into the grant investigation with Program Officers Rosie Bettle and Alice Redfern, discussing the timeline, modeling approach, and what ultimately led us to make the grant.Elie, Rosie, and Alice discuss:The grant investigation timeline: GiveWell completed the investigation in about six weeks from start to finish. Typically, GiveWell grant investigations build on months or years of prior research. While we’ve researched and funded malnutrition programs in the past (including ALIMA’s programs), this program’s scope was wider—covering primary healthcare, disease surveillance, and hospital logistics.  How we adapted our modeling: As part of evaluating this grant, GiveWell attempted to estimate several parameters related to mortality, then used a series of simple models—rather than one comprehensive model—to estimate cost-effectiveness based on those parameters. These models, along with conversations with experts and other inputs, allowed the team to move quickly and respond to the urgent need. An update on grant progress: With GiveWell’s funding, ALIMA’s program is now up and running again. The program has been adapted to incorporate mobile clinics, and ALIMA is on track to treat the number of children GiveWell expected. Based on a number of conversations, we believe that ALIMA’s programs are leading to increased care-seeking behavior. As GiveWell’s research team grows, that increased capacity and expertise allows us to evaluate a wider range of programs and adapt our approaches to better find the most cost-effective opportunities to help people. In this case, that growth enabled us to move quickly and navigate uncertainty to evaluate and fund ALIMA’s program.  Visit our Foreign Aid Funding Cuts page to learn more about our response to this year’s aid cuts, visit the All Grants Fund page to learn more about how you can support this work, and listen or subscribe to our podcast for our latest updates.This episode was recorded on December 3, 2025 and represents our best understanding at that time.