I assume the answer to this question is already known by the majority of the community and mostly interesting to newbies like myself. But, since I haven't found it answered after a bit of searching and I think it is relevant, it might be of value to some people.
As far as I know, GiveWell estimates that in 2020 the cost of saving the life of a child in the developing world is at 2300$.
I have two questions on this:
(i) I assume the exact calculation are pretty complicated, but could someone give me a rough overview of the steps they took to arrive at that figure?
(ii) What does "saving a life" mean here exactly? Does it mean "avert the death of someone by any amount of time" or "cause the extension of life (for one or a many) by a total of the expected life span of someone in the given region"? I assume its the latter, but it would be nice to have a confirmation.