GiveWell Conversations

What a Decade of Iron Funding Has Taught Us

Anemia, which is commonly caused by iron deficiency, can cause fatigue, cognitive impairment, and complications during pregnancy—and it affects roughly a quarter of the world’s population. Over the last decade, GiveWell has directed nearly $50 million to programs to address this health issue.  Because of the large number of people affected and the low cost to provide people with iron, we are evaluating additional iron fortification and supplementation programs to potentially increase our grantmaking in this area. At the same time, it has been difficult to determine exactly how much providing people with additional iron improves their lives. GiveWell’s growing research capacity is allowing us to study the programs we’ve funded and to support new research, then to use what we learn to continue improving our funding decisions. In this episode, GiveWell co-founder and CEO Elie Hassenfeld speaks with Researcher Andrew Martin about GiveWell’s work on iron: why the evidence is more complicated than it might seem, what we’ve learned from years of funding iron programs, and what’s ahead. Elie and Andrew discuss: * The evidence for iron: Anemia is a significant problem, but it can be hard to determine the exact magnitude of the benefit that comes from addressing it. In addition, current definitions of anemia, which can be caused by iron deficiency, are based on statistical data about typical hemoglobin levels rather than on people’s symptoms. GiveWell is supporting a randomized controlled trial [https://www.givewell.org/research/grants/Walter-and-Eliza-Hall-Institute-of-Medical-Research-Grant-for-Iron-Repletion-RCT-January-2025] in Bangladesh that aims to address this by measuring how providing additional iron affects perceived fatigue and other health outcomes—helping determine measurable thresholds at which people experience significant symptoms. We think the findings could reshape our understanding of how anemia affects people's lives and improve our anemia-related grantmaking. * Looking back at Fortify Health’s progress: Fortify Health partners with wheat flour mills in India to fortify flour with iron and other micronutrients. After earlier grants [https://www.givewell.org/research/incubation-grants/fortify-health/august-2019-grant] to Fortify Health providing general support, GiveWell made a larger $8.2 million grant [https://www.givewell.org/research/incubation-grants/Fortify-Health-expansion-December-2021] in 2021. At the time GiveWell made this grant, Fortify Health was working with seven mills and reaching roughly 350,000 people per year. Over the next three years, it expanded to 125 open-market mills producing more than 30 times more flour (see chart below) at about half the cost per person reached of our original estimate. We now estimate that our 2021 grant was about twice as cost-effective as we initially projected. Based on this track record, we recently renewed our support to Fortify Health with a $10 million two-year grant. * What’s next for GiveWell’s research into iron: GiveWell currently supports two iron programs in India: Fortify Health’s work expanding iron fortification of wheat flour and Evidence Action’s iron and folic acid supplementation program for schoolchildren. To date, GiveWell has not funded iron fortification or supplementation programs in Africa, despite the region’s high anemia burden, in part because of concerns about potential harm from iron interventions in high-malaria settings. To help expand our work in this area, we issued a request for information for iron programs [https://blog.givewell.org/2026/03/02/givewell-launches-rfis-for-targeted-vaccination-outreach-in-three-countries-and-anemia-control-programs-in-africa/] earlier this year—focusing on lower-malaria contexts—and are currently evaluating responses. We’re also considering support for historical research studying countries that have introduced fortification programs to help assess the long-term income effects of providing iron.  GiveWell’s research on iron supplementation and fortification programs exemplifies this moment in GiveWell’s evolution: The research capacity and track record we’ve built are now enabling us to assess past grants, build and evaluate the evidence base, and expand our support of new cost-effective ways to help people in need. Visit our All Grants Fund [https://www.givewell.org/all-grants-fund] page to learn more about how you can support this work, and listen or subscribe to our podcast [https://givewell.transistor.fm/subscribe] for our latest updates. To learn more about how we’re learning and improving by analyzing past grants, like the one described in this episode, join our webinar on June 9. Elie will moderate a conversation with Program Directors Alex Cohen and Julie Faller about our grant lookbacks methodology, what we’ve learned, and how the findings are informing our grantmaking. Learn more and register. [https://events.zoom.us/ev/AuSIrbykuKHL-teUj0PIe0Gp_jui_DoZuNRGi7acruC1VnDGw4a0~As_dVgVQJ5Wv-r7kYqc2vkPr8eZSgQbkjpe2jd9L4cRrK92rLQk9qMRQUEPdySEs4PUHQC31d_s_laJfkKqObRPzDA] This episode was recorded on May 15, 2026 and represents our best understanding at that time.

Behind the Analysis: Assessing Past Malaria Nets Grants

GiveWell’s research doesn’t end once we’ve made a grant. We evaluate a subset of completed grants, comparing what we thought would happen to what actually took place, then try to use what we learn to improve our future funding decisions. Over the past year, we’ve formalized and expanded this work, publishing comprehensive “lookbacks” for select grants. A recent lookback on grants GiveWell made to fund insecticide-treated net distributions supported by the Against Malaria Foundation (AMF) in the Democratic Republic of Congo (DRC) illustrates the growing capacity of GiveWell’s research team. We drew on multiple independent data sources, funded qualitative interviews to gather more information, and conducted a novel empirical analysis to deepen our confidence. In this episode, based on a conversation originally aired on GiveWell’s internal podcast for staff, GiveWell’s co-founder and CEO Elie Hassenfeld provides additional context while GiveWell’s Chief Research and Program Officer Teryn Mattox dives deep into the details with Program Director Alex Cohen and Researcher Steven Brownstone, examining how we conducted the lookback, what we found, and how what we learned may shape our future nets grantmaking.  Elie, Teryn, Alex, and Steven discuss: * A more expansive and rigorous approach to evaluating past grants. This lookback draws on three independent quantitative sources—AMF’s monitoring data, a recent Demographic and Health Survey (DHS) conducted in the DRC, and an original survey commissioned by GiveWell—alongside qualitative research involving in-depth interviews with people involved in DRC’s net distribution system, from health zone administrators to village focus groups.  * Conducting a novel mortality analysis using DHS microdata. Because net campaigns roll out on staggered schedules across DRC’s provinces, we were able to use the timing of children’s births relative to the date of local net campaigns as a natural experiment. We compared mortality risk for children based on when they were born, and thus the length of time they had protection from a net, and found that the net campaigns reduced the risk of death by around a quarter. That finding provides additional support for the mortality effect estimate we use in our cost-effectiveness models. * What qualitative research revealed. Interviewers asked people across five provinces in DRC whether households received nets and whether households were using nets—and in cases where they either didn’t receive nets or weren’t using them, why not. Although we heard some anecdotes of misuse or diversion of nets, the data suggested overall that the nets are highly valued by the communities receiving them.  * How durability data could inform campaign design. Our analysis of DHS data confirmed earlier research indicating that nets in DRC degrade before they are replaced through new distributions. As a result, it’s possible that changes in DRC like more frequent campaigns or increased support of routine net distribution through other channels may increase protection.  If you’re interested in learning more about grant lookbacks like this one—and how they’re improving our research and shaping our future funding decisions—we invite you to join our next webinar on June 9. Alex Cohen, who was featured in this episode, and Program Director Julie Faller will walk through our lookback process, what we’re learning, and how we’re applying those lessons to help more people. Learn more and register here [https://events.zoom.us/ev/AuSIrbykuKHL-teUj0PIe0Gp_jui_DoZuNRGi7acruC1VnDGw4a0~AgDx7CkfisUuffpSSL7A16lIu4P5vZ1GWyqqZoGLzuSzNv6hF18YIB8HxDgqp85d8lrzfkp0FONz1S_Hs3A0_ydpjw]. This episode was recorded on April 22, 2026 and represents our best understanding at that time. -- Glossary Because the conversation in this episode first aired as part of GiveWell’s internal podcast for staff, there are a number of names, acronyms, and other terms that are not explained. To make it easier to follow along, we’ve provided a glossary below.  * all-cause mortality. All-cause mortality measures the total number of deaths from any cause in a specific group of people over a specific period of time.  * AMF. The Against Malaria Foundation [https://www.givewell.org/charities/amf], one of GiveWell’s Top Charities [https://www.givewell.org/charities/top-charities], collaborates with national malaria programs and other partner organizations in low- and middle-income countries to distribute insecticide-treated nets.  * CEA. We build cost-effectiveness analyses [https://www.givewell.org/how-we-work/our-criteria/cost-effectiveness/cost-effectiveness-models] to assess how much good can be achieved by giving money to a certain program.  * Cox proportional hazards model. The Cox proportional hazards model [https://en.wikipedia.org/wiki/Proportional_hazards_model] is used to estimate how much different factors, such as time since an insecticide-treated net campaign, speed up or slow down the time to death. It assigns each factor a “hazard ratio,” which is a multiplier of the baseline risk of dying: a hazard ratio of 2 for smoking means that smokers face double the risk of death at any given moment compared to nonsmokers, all else equal.  * DHS. Demographic and Health Surveys [https://blog.givewell.org/2025/08/21/podcast-episode-10-the-fragile-foundations-of-global-health-data/] are vast, in-person surveys that ask women to recall their children’s birth and survival histories. This method provides the primary data for mortality estimates in low- and middle-income countries. * funging. What we call “funging [https://blog.givewell.org/2024/06/21/the-fungibility-question/]” (from fungibility) refers to the effect of crowding out funding that would have otherwise come from other sources.   * insecticide-treated nets. These nets have been treated with insecticide to deter and kill the mosquitoes that transmit malaria. Distributing insecticide-treated nets [https://www.givewell.org/international/technical/programs/insecticide-treated-nets], which are then hung over sleeping spaces, can be a cost-effective way of preventing malaria. * lookbacks. Lookbacks are reviews of past grants published on the GiveWell website that assess how well they’ve met our initial estimates and what we can learn from them. * Marakuja. Marakuja Kivu Research [https://marakuja.org/] is a nonprofit organization in DRC that we have contracted with to conduct quantitative and qualitative surveys.  * M&E. GiveWell asks organizations that we fund to share detailed monitoring and evaluation data on their programs to assess the quality of program implementation and whether it is reaching recipients as intended.  * net durability. Insecticide-treated nets decay over time [https://www.givewell.org/international/technical/programs/insecticide-treated-nets#How_long_does_each_net_provide_protection], both through loss of insecticide and physical wear. * nets team. In internal conversations, this is what we sometimes call our vector control team (see below for definition).   * OnFrontiers. OnFrontiers [https://www.onfrontiers.com/] is a company that sets up interviews with subject matter experts around the world.   * PDM....

Evaluating and Funding a New Kind of Grant (Clubfoot Treatment)

Clubfoot, a congenital condition where children are born with one or both feet twisted inward, affects roughly one in 800 newborns globally. Most of those cases are in low- and middle-income countries, where only about 20% of children with clubfoot receive treatment.  While most donations to GiveWell are directed to programs that reduce child mortality, our growing research capacity over the last several years has expanded what we’re able to evaluate and fund. One outcome of that work is that we’re better able to direct donations to highly cost-effective programs addressing disabling conditions, like clubfoot, and meaningfully improve quality of life.     In this episode, GiveWell CEO and co-founder Elie Hassenfeld speaks with Program Officer Meika Ball about GiveWell’s grant [https://www.givewell.org/research/grants/miraclefeet-clubfoot-treatment-january-2023] to MiracleFeet, an organization that expands access to clubfoot treatment. Their conversation walks through MiracleFeet’s program, how we estimated its cost-effectiveness, and Meika’s recent site visit to see the program in action in Côte d’Ivoire. Elie and Meika discuss: * How MiracleFeet supports clubfoot treatment: Clubfoot is treated using the Ponseti method, which involves casts to correct the foot’s position, a small surgical procedure, and a period of bracing. MiracleFeet supports this treatment by partnering with local health facilities, training healthcare workers, educating local communities about clubfoot, providing treatment materials, and working with Ministries of Health. Because of this support, treatment is provided at no cost to patients or their caregivers. GiveWell-funded independent surveys in Côte d’Ivoire and Chad indicated that very few children with clubfoot were being treated before the program, and hundreds have been enrolled since the program’s launch. * What we learned from a recent site visit: Two GiveWell staff members recently traveled to Côte d’Ivoire to visit health facilities and see children being treated through MiracleFeet’s program. We spoke with a range of stakeholders, including healthcare workers, implementing partners, representatives from the Ministry of Health, caregivers of children receiving treatment, and disability advocates. Seeing the program in action increased our confidence that it is leading more children with clubfoot to receive treatment and is having an important impact on their lives. We also saw early signs of the program being integrated into national health systems, such as clubfoot being added to a maternal child health booklet that parents and midwives review after a child is born.  * What makes this grant different: Most of GiveWell’s grantmaking focuses on preventing child deaths from widespread conditions like malaria or diarrhea. Clubfoot is a relatively rare condition that causes disability, not death. The treatment costs more per child than many other programs we fund, such as distributing vitamin A supplements or malaria nets, and requires sustained caregiver adherence over several years. To assess this grant opportunity, GiveWell applied moral weights [https://blog.givewell.org/2025/07/17/apples-oranges-and-outcomes/], or subjective valuations, for the impact of clubfoot so it could be compared with other programs’ outcomes. We also made a separate grant [https://www.givewell.org/research/grants/miraclefeet-monitoring-and-evaluation-may-2023] to support monitoring and evaluation of the program to assess how much MiracleFeet’s support increases the number of children receiving appropriate and effective treatment.  Our ability to evaluate, fund, and monitor a program like MiracleFeet’s is possible because of years of investment in our research team. This program exemplifies how our growing capacity is enabling us to expand our search for cost-effective opportunities where donors can do exceptional good. Visit our All Grants Fund [https://www.givewell.org/all-grants-fund] page to learn more about how you can support this work, and listen or subscribe to our podcast [https://givewell.transistor.fm/subscribe] for our latest updates. This episode was recorded on March 30, 2026 and represents our best understanding at that time.

Scrutinizing One of Our Longest-Funded Programs

Vitamin A supplementation is one of the programs GiveWell has supported the longest, and we’re currently funding it in many African countries. The program has an unusually strong evidence base for reducing child mortality, with multiple randomized controlled trials. Yet, as is the case for most global health programs, the evidence for vitamin A supplementation has complex, unresolved questions, such as how well findings from decades-old trials apply today and the extent to which existing research has been influenced by publication bias. As GiveWell’s research team has grown over the last several years, we have expanded our capacity to carefully research these questions.  In this episode, GiveWell CEO and co-founder Elie Hassenfeld speaks with Senior Researcher Stephan Guyenet about the evidence base for vitamin A supplementation, the complications in applying that evidence to our funding decisions, and how GiveWell has improved our cost-effectiveness estimates for the program. Elie and Stephan discuss: * The evidence base for vitamin A supplementation: Evidence from rigorous trials shows that vitamin A supplementation can significantly reduce child mortality. However, most of these trials were conducted 30 to 40 years ago, when infectious disease rates and vitamin A deficiency were more prevalent, and a more recent large trial in India found a much smaller effect. As a result, we worked to resolve our uncertainties about the effect of vitamin A supplementation in the contexts where we’re supporting it today.  * How GiveWell worked through the complications: To address our questions about the existing evidence, we engaged in further research. This included an analysis focused on the specific diseases for which vitamin A supplementation reduces mortality, a novel dosing-frequency analysis conducted in consultation with an outside statistician, and an assessment of possible publication bias.  * What all of this means for grantmaking: While the trials report that vitamin A supplementation reduces the risk of death by 19% on average in children 6 to 59 months old, we estimate that the impact in the modern settings we model is smaller: a 1% to 11% lower risk of death. Nevertheless, we still think vitamin A supplementation can be highly cost-effective. Using our updated cost-effectiveness analysis, we estimate our most recent grant for vitamin A supplementation to Helen Keller Intl is 25 times more cost-effective than our benchmark. This change reflects our more precise, location-specific analyses that allows us to direct funding to places where vitamin A supplementation is likely to be the most cost-effective.  GiveWell continues to scrutinize the programs we fund, including those we have supported for years. In this case, years of rigorous research have largely held up the case for vitamin A supplementation. We will continue to review the program, funding new research to address remaining uncertainties and exploring whether a new randomized trial might be feasible. By doing so, we’ll continue to increase our confidence and refine our funding decisions to target the most cost-effective locations and do the most good we can with donors’ funds. Visit our All Grants Fund [https://www.givewell.org/all-grants-fund] page to learn more about how you can support this work, and listen or subscribe to our podcast [https://givewell.transistor.fm/subscribe] for our latest updates. This episode was recorded on March 25, 2026 and represents our best understanding at that time.

Investing in Information for Greater Future Impact

GiveWell’s primary focus has always been researching, identifying, and directing donations to programs we believe will do the most good. When GiveWell first started, we approached this by looking for organizations that were already delivering highly cost-effective, evidence-backed programs and directing funding to those programs. Over time, we were able to focus further upstream by first identifying highly cost-effective programs and then supporting the development of organizations to deliver them.  We’ve been able to take an even more expansive view as our research team doubled in size over the last several years. In addition to our core grantmaking, we’re now funding an increased number of grants designed to provide information that we think will help us direct more funding to highly cost-effective programs in the future. This includes things like generating research about program effectiveness, scoping new promising programs, and piloting program variations.   GiveWell has long made some grants aimed at improving our knowledge base, but this work has now grown substantially and become more systematic. In 2025, GiveWell made 18 grants, totaling approximately $39 million, that were aimed specifically at getting more information to improve future funding decisions. In our latest podcast episode, GiveWell CEO and co-founder Elie Hassenfeld speaks with Program Director Julie Faller about these “value of information” grants. Elie and Julie discuss: * Testing variations on cash transfers to improve cost-effectiveness: Following an initial scoping grant, GiveWell recently funded GiveDirectly to pilot three program variations aimed at increasing the economic impact of its flagship program, which provides unconditional cash transfers to very poor households. Each pilot tests a different approach to increasing impact: one provides grants to local businesses ahead of a cash transfer rollout, another targets transfers to the poorest young adults, and the third pairs transfers with footbridge construction to help remote communities access markets and services. Through these pilots, we expect to learn more about the feasibility and potential cost-effectiveness of the program variations, potentially leading to opportunities to help people in need even more.   * Testing a delivery model for diarrhea treatment: Oral rehydration solution—an inexpensive, effective treatment for diarrhea-related dehydration—is used by far fewer children than could benefit from it. To explore whether door-to-door delivery could increase uptake, GiveWell funded [https://www.givewell.org/research/grants/clinton-health-access-initiative-oral-rehydration-solution-zinc-bauchi-nigeria-september-2023] a large randomized controlled trial with the Clinton Health Access Initiative in Bauchi, Nigeria. Initial results are promising, indicating that 3,000 community distributors were able to reach about 80% of households with young children—and that ORS usage increased as a result. GiveWell is now considering whether to fund this model at scale, potentially with multiple implementers. * Collecting better data on a nutrition program in India: GiveWell has supported [https://www.givewell.org/research/incubation-grants/Fortify-Health-expansion-December-2021] Fortify Health, which works to address widespread anemia in India by partnering with flour millers to fortify wheat flour with iron. GiveWell recently funded a household survey in six Indian cities to better understand how much fortified flour people are actually consuming, and who in the household is eating it. The survey provided more information about several parameters that, taken together, allowed us to resolve some uncertainty about the program’s cost-effectiveness. We used what we learned to inform our decision to renew funding for the program.   These examples reflect a longer-term shift at GiveWell—from an organization that primarily evaluated existing programs to one that increasingly generates the evidence needed to improve its grantmaking and fund more impactful programs in the future. Visit our All Grants Fund [https://www.givewell.org/all-grants-fund] page to learn more about how you can support this work, and listen or subscribe to our podcast [https://givewell.transistor.fm/subscribe] for our latest updates. This episode was recorded on March 13, 2026 and represents our best understanding at that time.