There's an old joke about a man, head down, slowly walking in circles under the light of a street lamp. It is dark and he has lost his wallet.
A passerby offers his assistance and asks what they're looking for. A second does the same.
Finally, this second helper asks "Is this where you lost it?"
"No," comes the reply.
"Then why are you looking over here?"
"Because this is where the light is!"
The tendency to look for answers where they can be measured or found may also be present in psychological research on rats. We don't really look at rats for psychological insight because we think that's where the psychological insights are, that's just the only place we can look! (Note, I know looking at rats is better than nothing, and we don't only look at rats).
Likewise, GiveWell. They've released their new list of seven charities they recommend donating to. Six are efforts to increase health in a cheap way, and the last is direct money transfers to help people break out of poverty traps. In theory, these are the most cost-efficient producers of good in the world.
Except, not really. Technological research, especially AI, or perhaps effective educational reform, or improving the scientific community's norms might very well be vastly more fruitful fields.
I don't think these are all missing from GiveWell's list only because they don't measure up, but because, by GiveWell's metrics, they can't be measured at all! GiveWell has provided, perhaps, the best of the charities that can be easily measured.
What if the best charities aren't easily measurable? Well, then they won't just not be on the list, they can't be on the list.