One of the charities mentioned in the article, Deworm the World, is actually a Givewell top charity, due to “the strong evidence for deworming having lasting impact on childhood development”. The article, on the other hand, claims that the evidence is weak, citing three studies in the British Medical Journal, which Givewell doesn’t appear to mention in their review of the effectiveness of deworming.
Givewell’s review of deworming
Might be worth looking into more.
Something that should have occurred to me—the deworming experiment was done in the late 90s, which means that the effect on lifetime income is an estimate.