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.