This is an excellent article. A quick comment on one of the sentences:

GiveWell.org, a site which collects and interprets data on the effectiveness of charities, predicts that antimalarial drugs save one child from malaria per $5,000 worth of bed medicine, but insecticide-treated bed nets save one child from malaria per $500 worth of drugs.

I find this sentence somewhat confusing. Should the "worth of bed medicine" be just "medicine", and the "worth of drugs" be "worth of netting"?