The GiveWell Blog

September 2019 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 our June 2019 open thread here.


  • Bill Goodykoontz on September 13, 2019 at 10:20 am said:

    I have recently read Melinda Gates’ book “The Moment of Lift” and have been reflecting on her belief that “contraceptives are the greatest life-saving, poverty-ending, woman-empowering innovation ever created”, among many other issues she raises. I wonder if GiveWell has reviewed some of the NGO’s she recommends such as BRAC, Tostan, or the Community Empowerment Lab, among others. I’m also curious about your feelings about donating to the Gates Philanthropy Partners “Empowerment & Opportunity Fund”. Thank you so much for all of your dedicated and life-saving work.

  • Erin Wolff on September 17, 2019 at 1:43 pm said:

    Hi Bill, thanks for your message! We have not reviewed the organizations you’ve mentioned for their work in contraceptives and/or family planning. (We had initially researched BRAC for all their programs; the review page can be found here, but please note it is likely to be out-of-date). We have worked on an investigation of family planning groups, though we haven’t yet published it. Here are some related links on our website:

    • David Roodman’s investigation into the connection between mortality rates and fertility rates: here. There is some discussion of our view on family planning programs in the comments.
    • Our review of Sayana® Press, an injectable contraceptive: here.
    • Notes from our conversation with the Hewlett Foundation on family planning: here.

    Unfortunately, we haven’t researched the Gates Philanthropy Partners’ “Empowerment & Opportunity Fund,” so we don’t have a sense of how cost-effective the programs it funds are or what its funding needs look like.

  • Any thoughts on the recent update to the Cochrane review on mass deworming, including six new trials since the 2015 edition, but reaching the same conclusion: “Public health programmes to regularly treat all children with deworming drugs do not appear to improve height, haemoglobin, cognition, school performance, or mortality.”

    As more evidence accumulates, GiveWell’s position that possibly there are some possibly some spectacular later-life financial benefits of deworming though an unclear mechanism looks increasingly odd. You might also have noticed that even the advocates of mass deworming (see for example Pullan et al, Lancet, 2019) now generally make no direct mention of individual benefits of deworming, but rather talk about WHO eradication goals. So GiveWell is rather out on a limb in agreeing with those that hypothesise these possible later-life benefits.

    How many negative trials of mass deworming impacts do you need to see to make a re-evaluation of your recommendations ?

    Link here

  • James (GiveWell) on October 12, 2019 at 11:49 am said:


    Thanks for your engagement with our work. A few points of clarification and response.

    Our position on deworming

    – We agree it’s unlikely there are very large later-life financial benefits of deworming (e.g. the estimated ~14% increases in earnings from Baird et al), due in part to a prior that such effects would be unlikely, and in part because of the lack of clear evidence for a mechanism. We discount the headline results of Baird et al heavily to account for that. Instead, we believe that there is some chance of relatively small impacts on earnings on a large number of infected children. (more in this blog post)

    – We continue to believe deworming is (in expectation) a highly cost-effective intervention in areas with high worm burdens, based largely on our estimate that it costs under $1 for each child dewormed in most settings in which our charities operate (source).

    – Unfortunately, this leaves us in a difficult position as the minimum effect size of interest is small and difficult to detect (or falsify). We’ve funded work to try to falsify our conclusions but have not found an opportunity to support research that could realistically falsify our view. That includes longer term follow-ups to Baird et al, and a scoping grant to assess whether other RCTs might be amenable to long term follow-up to estimate the effects of different interventions on long run income.

    – Given the difficulty of definitively proving or falsifying the case for deworming, our recommendation necessarily relies on difficult judgment calls. We’re uncertain about those judgement calls and know we might be wrong, but they represent our best guess of what to take away from the accumulated body of evidence (that mass deworming has, in expectation, a small effect on long run income and is very cheap to administer). We’ve strived to be open and transparent about that (see here and here).

    The studies you mention

    We haven’t reviewed Pullan et al or the 2019 updated Cochrane review in depth, but we have read through them. They don’t currently change our conclusions, and we don’t expect that they will once we review them more thoroughly (though we plan to do that in the future). That’s because:

    -In the 2019 Cochrane review, the mean estimate of weight gain appears to have increased slightly, and the null effect of height gain appears to be slightly more precisely estimated than in the previous version, which we don’t think is likely to be a substantial negative update on balance.

    -The Pullan et al. study appears to be a comparison of different delivery platforms for combination deworming, rather than an evaluation of deworming itself.

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