The GiveWell Blog

January 2024 updates

Every month we send an email newsletter to our supporters sharing recent updates from our work. We publish selected portions of the newsletter on our blog to make this news more accessible to people who visit our website. For key updates from the latest installment, please see below!

If you’d like to receive the complete newsletter in your inbox each month, you can subscribe here.

Recent GiveWell events

We ended 2023 with two in-person events, one in New York and one in San Francisco.

In San Francisco, GiveWell’s CEO Elie Hassenfeld was joined by Neil Buddy Shah, CEO of the Clinton Health Access Initiative (CHAI), to discuss the work of both organizations and their partnership via the CHAI Incubator. You can find the audio recording and transcript of this event here.

In New York, Elie spoke with journalist Matthew Yglesias, co-founder of Vox and creator of Slow Boring, about GiveWell’s top charities and latest research. You can check out the video recording and transcript of this event here.

Attending events is a great way to learn more about GiveWell! You can sign up here to be notified of in-person and virtual events, and you can catch up on our previous events here.

GiveWell in the Media

Teryn Mattox, Director of Research at GiveWell, wrote a guest essay for Emily Oster’s Substack, ParentData, on the effectiveness of kangaroo mother care (KMC). KMC is intended to be a low-cost alternative to conventional neonatal intensive care for low-birth-weight infants; it primarily involves skin-to-skin contact between mother and baby. In low- and middle-income countries, KMC can save babies’ lives, but implementation can be challenging. GiveWell’s research on and grantmaking to maternal and newborn health programs includes a grant to r.i.c.e., which operates a KMC program in India.

Research Updates

We’ve recently published a number of new research pages—below are a few highlights. If you’d like to sign up for email updates whenever we publish new research materials, you can do so here.

  • Clinton Health Access Initiative (CHAI)
    • In September 2023, GiveWell recommended a $6.6 million grant to CHAI for a two-year diarrhea treatment program in Bauchi, Nigeria. This grant supports the distribution of oral rehydration solution (ORS) and zinc to households with children under the age of five. Diarrhea is a common cause of childhood mortality in Nigeria, and we roughly estimate that this program will avert the deaths of approximately 2,000 children. This grant also supports a study to measure how much the use of ORS and zinc increases when they are provided free to households, which will help us learn more about the program.
  • Updated reports on GiveWell’s top charities and their interventions
    • We recently updated our reports on two of GiveWell’s top charities and their interventions. We updated our reviews of the mass distribution of insecticide-treated nets and the Against Malaria Foundation, which implements net campaigns. We also updated our review of seasonal malaria chemoprevention (SMC) and Malaria Consortium, which supports SMC campaigns. The new reports aim to more clearly explain our views of each program, so that readers can more easily understand the key factors underlying our recommendations, evaluate the ways we might be wrong, and provide feedback that will improve our research.
  • One Acre Fund
    • Last year, we checked in with One Acre Fund to follow up on a $1.3 million grant GiveWell recommended in January 2023 to run a study on its tree program in Rwanda. In this conversation, they discuss plans for the study, including their seedling distribution plan, how they selected the sites for the trial, and their plans for evaluating the program internally.

Other Updates on GiveWell’s work

  • GiveWell A-Z
    • We created a GiveWell A to Z highlighting a few key things about GiveWell. This short list is a fun and easy way to introduce a friend to GiveWell!
  • Approaching uncertainty in our cost-effectiveness models
    • We recently received criticism that we should model uncertainty more explicitly in our cost-effectiveness analyses. GiveWell researchers carefully considered these critiques, some of which won awards in our Change Our Mind contest. On this page, we discuss how we model uncertainty in our research, the adjustments that we make to combat these issues, and how we’re changing our approach in response to the criticism we received.
  • GiveWell’s impact in 2022

Your questions, answered

The mailbag spotlights common questions we get from donors and followers about GiveWell’s work. Got a question of your own? Email us at, or post a comment to our most recent open thread.

Q. What percentage of Give Well resources are dedicated to finding new programs versus funding proven organizations, like top charities?

A. In 2022, we directed over $340 million to our top charities (and former top charities) and over $80 million to other organizations and programs (which includes all newer-to-us programs). That being said, we are equally open to both newer and more familiar programs. Our goal is to look for the most cost-effective opportunities, regardless of program or location, so we use the same cost-effectiveness bar across all our grantmaking.

Our researchers typically focus on general cause areas that we’ve found promising, such as malaria, vaccines, water quality, and nutrition. Within these areas, researchers evaluate opportunities to support interventions we know well (for example, our top charities) as well as newer programs (for example, the recent innovations in malaria vaccines). We also have a dedicated New Areas team of four staff who focus on finding and researching interventions and funding opportunities that are newer to us, including via our partnerships with CHAI and Evidence Action.


  • What do you think about this new article?

    In Papua New Guinea, where malaria cases rose 88% in 2022, researchers found that nets made before 2012 were all effective in killing or incapacitating mosquitoes. But only 17% of those manufactured in the past decade did the same. The reason? Vestergaard, the Swiss company that produces PermaNet 2.0 — which has been used in Papua New Guinea and more than 100 other countries — switched to a cheaper coating researchers say rendered the insecticide less potent, but it didn’t inform the World Health Organization of the change until at least 2017.

    • Isabel Arjmand (GiveWell) on March 4, 2024 at 8:33 pm said:

      Hi Phil, thanks for asking! Like the Bloomberg editorial board, we’re concerned about stalling progress in the fight against malaria, but we’re skeptical that quality issues with PermaNet 2.0s have influenced this progress as much as the article suggests.

      All things considered, we believe that malaria nets are, and have been, highly effective in reducing malaria burden. The Against Malaria Foundation had first shared the studies highlighted above with us in 2020, and the claims in the Bloomberg article have prompted us to do some additional research.

      Based on the work we’ve done so far, we aren’t convinced that decreased net quality is primarily responsible for malaria resurging in Papua New Guinea. So far, we see this as a more mild negative update on nets, in part because we think these tests of net quality may not be a perfect proxy for effectiveness in reducing cases and in part because we no longer fund PermaNet 2.0s (for unrelated reasons). At the same time, renewed interest in the evidence around PermaNet 2.0 quality is a nudge for us to prioritize further work to understand net quality control in general.

      More detail on the implications of this research
      While we no longer fund PermaNet 2.0s because we now fund newer types of nets instead, they make up roughly 20% of nets we’ve funded historically. The studies referenced in the Bloomberg article looked at nets distributed in Papua New Guinea and indicate that the post-2012 PermaNet 2.0s perform worse on certain efficacy tests. We aren’t sure how well those efficacy tests serve as a proxy for malaria transmission (e.g. mosquitoes in these tests could be impaired from the exposure to insecticides even if it isn’t sufficient to kill them). We’re also skeptical that changes to the formulation of PermaNet 2.0s were the key driver of increased malaria cases in Papua New Guinea. During this time, we think other factors like insecticide resistance and shifts in biting patterns likely played a meaningful role (as highlighted in this paper: That said, we see these studies as a negative update on the effectiveness of those nets.

      We did a quick back-of-the-envelope calculation (so this is more illustrative than fully baked, at this point):
      (1) Assuming the insecticide treatment on PermaNet 2.0s was 80% less effective after 2012 would make those nets look 30-50% less effective overall than we’d previously modeled. That’s because we model roughly 30% of the benefit of nets as coming from the physical barrier in the absence of insecticide resistance, and we already discount the effectiveness of nets like PermaNet 2.0 because of insecticide resistance. We would guess that with further work, we’d estimate that 80% is on the pessimistic side of things (which would put the overall impact on net efficacy at the low end of our 30-50% range, or lower).
      (2) Then, assuming that similar issues don’t apply to other nets (which could be wrong – we plan to look into this more), our overall nets grantmaking would look roughly 5-10% less cost-effective than we’d previously estimated, since PermaNet 2.0s are around 20% of our historical nets distributed. That proportion has varied over time. In 2018, all of the nets we funded were PermaNet 2.0s; now, we fund newer types of nets instead.

      While concerns specific to PermaNet 2.0s don’t directly affect our future allocation decisions, this issue does raise more general concerns about quality control for nets. Ideally, we would have prioritized more work in this area in the past. We’re planning to learn more about quality control processes and we also want to better understand how others in the malaria field are thinking about this.

      Please let us know if you have more questions about this.

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