Riceissa answered this on the LessWrong version of this question – the original source this facebook post by Vipul Naik.
For three different foundations: Open Philanthropy Project, Bill & Melinda Gates Foundation, and Laura and John Arnold Foundations, I calculated that the total money granted per hour of staff time is approximately $1000 - $3000. This includes all staff time (obtained by taking number of people on staff and multiplying by 2000 hours for a year, then comparing with annual grants).
Is there a reasonable argument that foundations would generally have this ratio of money granted to staff time? For instance, if we break down the cost into direct grant investigation cost + cost of time spent getting familiar with the domain and evaluating strategy, etc., are we bound to arrive at a comparable figure?
One foundation that has a much higher ratio of money granted to staff time in recent years is Atlantic Philanthropies, but they are in spend-down mode right now and I don’t have a good picture of their overall spend trajectory and employee counts yet.
Open Philanthropy Project: Grants in 2016: $50 to $100 million Staff at year-end: ~20 (+ some shared operational staff with GiveWell)
Laura and John Arnold Foundation Grants in 2015: $185 million Staff in 2016: ~50 listed on their site
Bill & Melinda Gates Foundation Grants: ~$4.2 billion Staff: ~1500
Riceissa answered this on the LessWrong version of this question – the original source this facebook post by Vipul Naik.