The GiveWell Blog

September 2022 open thread

Our goal with hosting quarterly open threads is to give blog readers an opportunity to publicly raise comments or questions about GiveWell or related topics (in the comments section below). As always, you’re also welcome to email us at or to request a call with GiveWell staff if you have feedback or questions you’d prefer to discuss privately. We’ll try to respond promptly to questions or comments.

You can view previous open threads here.


  • I am really happy with your blog because your article is very unique and powerful for new.

  • My question is about giving in the malaria prevention space. I’ve read some about RTS,S and R21 vaccines and it seems like 2023 and 2024 might see some really big changes, hopefully improvements in malaria impact.
    Obviously until R21 vaccine is proven chemoprevention and nets are the best solutions. Is GiveWell already planning on how to reassess giving for malaria prevention if vaccines prove out and are mass adopted?

  • Miranda Kaplan on October 5, 2022 at 12:24 pm said:

    Hi, Katie,

    Thanks, and good question! Malaria vaccines are an area we’re watching closely (and we have recommended funding to expand the RTS,S vaccine to comparator areas used in an ongoing pilot), but so far vaccine rollout hasn’t been extensive enough to change our evaluation of insecticide-treated nets and SMC.

    The impact of widely available vaccines on the cost-effectiveness of other malaria prevention measures will be an important question for us to consider in the future. There’s some evidence that vaccines don’t necessarily make other tools look less impactful—for example, one study found a synergistic effect between the RTS,S vaccine and SMC. More generally, using multiple malaria prevention tools at once can be complementary rather than redundant. For instance, WHO and Gavi have both described the RTS,S vaccine as best used as part of a package of malaria controls (see footnote 2 in our blog post on RTS,S), and WHO generally recommends a package of interventions, which can include combining nets or indoor residual spraying (IRS) with chemoprevention (see footnote 21 in our blog post on intermittent preventive treatment in infants for malaria).

    We’re continuing to monitor new evidence about malaria vaccines as it becomes available, and will incorporate it into our cost-effectiveness analyses for other malaria prevention programs as needed.

    I hope that’s helpful!


  • La Nest on October 9, 2022 at 1:07 pm said:

    I am really happy with your blog because your article is very unique and powerful for new.

  • La Nest on October 9, 2022 at 1:08 pm said:

    Your blog makes me incredibly pleased, and your content is particularly effective for new readers.

  • Miranda Pope on October 12, 2022 at 4:39 pm said:

    I hope there is consideration given to the possible negative effects of using insecticide-laden nets around the beds of babies and small children. My alarm-bells immediately went off on reading about this. It also makes me wonder what pesticide company is making money off producing these nets. I know you do research on all that you promote, but both these factors make me wonder about the ethics of this “malaria prevention” method.

  • Miranda Kaplan on October 14, 2022 at 2:25 pm said:

    Hi, Miranda,

    Thanks for your question! We haven’t independently dug into the question of insecticide-treated nets and chemical safety, but the net distribution campaigns supported by the programs we fund use only nets that have been pre-qualified by the World Health Organization. As part of the pre-qualification process, WHO assesses the health risks of the chemical proposed to treat the nets, taking into account the close contact they will have with the people using them. (WHO’s risk assessment reports for standard insecticide-treated nets are publicly available; here is an example.) There are relatively few pesticides that are allowed for use on nets, because very few have been approved by WHO for close human exposure on an ongoing basis.

    We have explored other possible health risks of insecticide-treated nets, including allergic reactions and fires, and described them here.

    I hope that’s helpful!


  • I am really happy with your blog because your article is very unique and powerful for new.

  • Ethan Kennerly on December 7, 2022 at 3:57 pm said:

    In a December 7th webinar, Kelsey Piper from Vox News asked Elie Hassenfeld:

    * How could the cost-effectiveness spreadsheets be more accessible?

    * Elie said he would like to make infant survival and adult income tradeoffs clearer.

    I have a follow-up question.

    Has GiveWell considered presenting two separate donation goals?

    (A) Infant survival.
    (B) Adult income.

    Rate each top charity on (A) and (B) separately. Ideally, to have a separate worksheet for (A) than (B). Hopefully, a donor would easily inspect (A) and (B) separately.

    Then the donor (or GiveWell) could aggregate (A) and (B) into an overall benefit according to their moral values.

    GiveWell spreadsheets already aggregrate (A) and (B). The goal of this question is to layout data points to focus on inspecting (A) and (B) separately. This might have an advantage of focusing each spreadsheet more on evidence rather than early-entanglement of the evidence with the assumption of the preferred moral tradeoff between (A) and (B).

  • Miranda Kaplan on December 14, 2022 at 1:46 pm said:

    Hi, Ethan,

    Thanks for the suggestion, and apologies for the delay in responding!

    We can see the value in having separate assessments of cost-effectiveness based on different outcomes. Child mortality reduction and adult income increases are two of the primary benefits we model from our top charities. However, we also model other benefits, such as reductions in over-five mortality and increases in immediate income. It’s not clear where we would include these benefits if we modeled child mortality reduction and adult income increases separately.

    While we don’t create separate cost-effectiveness estimates for different benefits, we do show what percentage of a program’s overall impact we expect to come from different types of benefits (see an example from our analysis of AMF here).

    We also know that others might disagree with the moral weight values we’ve chosen, which is why we’ve enabled users to enter their own moral weights for different outcomes, potentially changing the final cost-effectiveness estimate. See here. (Note that this doesn’t work perfectly for all our models. The final cost-effectiveness estimates in our AMF analysis won’t update in response to user-entered moral weights, because our leverage and funging calculations are informed by spending information that we don’t have permission to publish.)

    We make a number of judgment calls in building our cost-effectiveness analyses, and we know that our approach isn’t perfect. We’re always open to refining these models to make them more complete or more useful. Thank you again for your input!


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