The definition of Fermi estimate linked in this post defines a Fermi estimate as aiming to be within 1 magnitude of true. Given just the Rethink Priorities welfare range estimates span several magnitudes (infinite really, given lower bound is 0), this at least is incorrect.
This sort of chaining of EV calculations is common on this forum. I think it’s counterproductive. Show the confidence intervals and it becomes clear that the result is as good as “I have no idea”, which is a fine thing to say. Just say that.
Could you clarify the argument you are making? I agree the 5th percentile past cost-effectiveness of HSI is 0 given this is RP’s 5th percentile welfare range of shrimps. However, I think what matters is the expected cost-effectiveness. Are you suggesting one should disregard interventions whose 5th percentile cost-effectiveness is 0? Imagine one could pay 1 k$ to save 0 lives with 10 % probability, and 1 life with 90 % probability. The 5th percentile cost-effectiveness is 0 (the 5th percentile cost-effectiveness of deworming programs could also be super low?), but the expected cost-effectiveness is 0.9 life/k$, i.e. around 4.5 times the cost-effectiveness of GiveWell’s top charities of 0.2 life/k$ (= 1/(5*10^3)).
The definition of Fermi estimate linked in this post defines a Fermi estimate as aiming to be within 1 magnitude of true. Given just the Rethink Priorities welfare range estimates span several magnitudes (infinite really, given lower bound is 0), this at least is incorrect.
This sort of chaining of EV calculations is common on this forum. I think it’s counterproductive. Show the confidence intervals and it becomes clear that the result is as good as “I have no idea”, which is a fine thing to say. Just say that.
Could you clarify the argument you are making? I agree the 5th percentile past cost-effectiveness of HSI is 0 given this is RP’s 5th percentile welfare range of shrimps. However, I think what matters is the expected cost-effectiveness. Are you suggesting one should disregard interventions whose 5th percentile cost-effectiveness is 0? Imagine one could pay 1 k$ to save 0 lives with 10 % probability, and 1 life with 90 % probability. The 5th percentile cost-effectiveness is 0 (the 5th percentile cost-effectiveness of deworming programs could also be super low?), but the expected cost-effectiveness is 0.9 life/k$, i.e. around 4.5 times the cost-effectiveness of GiveWell’s top charities of 0.2 life/k$ (= 1/(5*10^3)).