I meant whoever produced figures for the ratios. I guess I was envisioning the Institute of Fundraising, but only because I recently saw some figures from them.
Edit: It seems Charity Science have an overview of this linked in another comment. They have a summary of other studies, but I don’t know the methodology for these other studies. They have a Fermi estimate themselves (and they don’t discount), but the error bars are large and I think this is more of a sanity check on the other figures—it’s not clear discounting should change the overall conclusion too much, except perhaps pushing against a focus on young people.
I meant whoever produced figures for the ratios. I guess I was envisioning the Institute of Fundraising, but only because I recently saw some figures from them.
Edit: It seems Charity Science have an overview of this linked in another comment. They have a summary of other studies, but I don’t know the methodology for these other studies. They have a Fermi estimate themselves (and they don’t discount), but the error bars are large and I think this is more of a sanity check on the other figures—it’s not clear discounting should change the overall conclusion too much, except perhaps pushing against a focus on young people.