Thanks for that, Steve! Interesting to skim over. It seems rather outdated and sketchy, the funding and charity situation in EA has changed dramatically since 2016. But you were probably aware of that yourself. Do you have any idea whether the number is actually used and therefore influential for individuals choices, or is it just a interesting number floating around? Depending on that you might want to consider to update the calculations.
What about Rutger Bregman, Dutch Historian and best selling author of 'HumanKind'. For EA interview see here
It's already being done, and seems to be pretty succesful. See this Founders Pledge profile and this interview with Erik Bergman.