# Matt_Sharp comments on Concerns about AMF from GiveWell reading—Part 3

• Thanks for your response—and more generally, thanks for putting time and effort into scrutinising GiveWell’s analysis, and sharing your views here.

Net distributions cover the whole community, they are not targetted at just under-5s. Using GiveWell’s figures, 16% of the population is under 5. Scaled up 1.8 people per net this suggests coverage for 1.4m * 16% * 1.8 = 0.4m young children.

You’re of course right. I originally wrote ‘people’ rather than ‘children’, but changed it because the discussion was focused on under 5 mortality.

That’s not going to materially change the mortality rate in a country with c.12m under 5s.

Sure—but the question is whether it changes the mortality rate of those receiving the bednets.

I can confirm that the 7.7 mortality rate is an unadjusted country-wide mortality rate and 11.9 is the rate GiveWell estimates would occur with no distributions from AMF.

I think you may be right, and it seems like GiveWell may have made a mistake here. But that doesn’t mean the mortality rate would be unchanged for those who receive (or would receive) bed nets. Rather, as I suggested before:

• mortality for those who do have bednets might be lower than the country-wide mortality rate. e.g. if bednets reduce mortality by 17%, then we might assume the mortality rate with bednets goes from 7.7 to ~6.4.

• then, if the AMF bednets are stopped, we might expect an increase in mortality back up to around the country average (which we presume indicates the mortality rate of those without bednets). So the increase would be 6.4 back to 7.7.

• I agree for those that get a net it’s a good thing and mortality is reduced, and also agree mortality would increase again if no further nets appeared. However this point isn’t material given the volumes involved. 0.4m children at a rate of 6.4 and 11.6m at a rate of 7.7 is an average rate of 7.66 for the 12m children in total.

Even this small effect is diluted further when you consider the 6.4 rate only applies for 1. 74 years after the 2014-2016 distributions, so much lower when you measure mortality in 2019.

Previous AMF distributions fall into the level of rounding error in this counterfactual, which is why I’m saying an uplift from 7.7 to 11.9 is unreasonable.

• I’m not sure I follow your point about volumes. The cost-effectiveness model is for those who receive the net. There’s no need to dilute the impact on these people merely because other people don’t experience the same impact. You just say ‘this is the benefit to these people, achieved at this cost’.

• I think we both agree that bednets give a 17% reduction in mortality. The question is what mortality rate to apply this 17% to.

GiveWell say 11.9.

I say 7.7.

Based on your points I thought you were either saying (a) 7.7, agreeing with me, (b) an adjusted version of 7.7, which I calculate to be 7.66. Either way we’re agreeing here.