In the LRB:

As a doctor with experience in international health I have found that some of the claims made by the proponents of effective altruism are not merely ‘satisfyingly counterintuitive’: they are wrong. For example, MacAskill claims that deworming has better educational outcomes among Kenyan schoolchildren than increasing the number of textbooks or teachers. This notion is based almost entirely on a single study published by Miguel and Kremer in the journal Econometrica in 2004 and has recently been debunked by Aiken, Davey et al in the International Journal of Epidemiology. Deworming does not improve educational outcomes. A review of the evidence available in the field of development studies makes it clear that improved educational outcomes in developing countries are best achieved by, wait for it, a decent, well-resourced school system. The idea that a single anti-worm pill is the key to solving the deep societal injustice of poor education is another instance of the glib ‘freakonomics’ style of thinking that has hijacked much of the field of social studies. Claims for a pharmacological magic bullet as a solution to poor educational attainment in Africa dovetail very nicely with the prevalent ideology of international health governance, which is content to accept structural inequalities in wealth and power while focusing on vertical, narrow, top-down, and ultimately ineffective strategies in alleviating health inequalities.

 (Thanks to Arthur Smith for the pointer.)

ADDENDUM:  Some EA apologists point me to this discussion of whether the original study was really "debunked."  It seems to me there is a lot of quibbling here about the word "debunk"; nothing in this discussion, in any case, shows that the LRB letter writer isn't entirely correct that "the evidence available in the field of development studies makes it clear that improved educational outcomes in developing countries are best achieved by…a decent, well-resourced school system."