But the thing with the de-worming experiment is they did know it worked. They were studying a procedure known to be beneficial and merely asking "is this beneficial also to our policy goal" and using as a pretext to deny people a known beneficial medical treatment (for 1-2 years as the system was rolled-out).

Which is to say this seems neither analogous to medicine or ethical in the same fashion to controls for medicines of unknown efficacy. Maybe, if somehow they had no choice but their "phased roll-out", they have a justification but otherwise, what were they even considering? Not treating people?

See: https://www.betterevaluation.org/resources/example/Primary_s...