And you could think AMF is 5x that, getting you to over 100.
Then you could think GiveWell itself (or other EA orgs) get you another 10x due to the multiplier effect, getting you to an overall CBR of 1000x.
Of course there’s lots of ways you could object to this too!
2) Another way you might get led to CBR of over 100 is that if you care mainly about long-run effects, and you think there’s a relatively narrow range of activities that clearly benefit the long-run. e.g. if you think preventing existential risk is the key proxy for a good long-run future, you might think most ways of spending money have about zero effect on that, while some opportunities have very positive effects (e.g. donating to the FHI), creating a very high-return on well targeted donations.
Just to clarify, I’m not claiming you can get 1000x returns, just that your view about the maximum spread of returns will effect the conclusion.
Some examples of how you could reason towards CBR of over 100:
1) It’s plausible Give Directly has a CBR of ~30 (just focusing on the short-run welfare effects). http://reflectivedisequilibrium.blogspot.com/2014/03/givedirectly-happiness-and-log-income.html
And you could think AMF is 5x that, getting you to over 100.
Then you could think GiveWell itself (or other EA orgs) get you another 10x due to the multiplier effect, getting you to an overall CBR of 1000x.
Of course there’s lots of ways you could object to this too!
2) Another way you might get led to CBR of over 100 is that if you care mainly about long-run effects, and you think there’s a relatively narrow range of activities that clearly benefit the long-run. e.g. if you think preventing existential risk is the key proxy for a good long-run future, you might think most ways of spending money have about zero effect on that, while some opportunities have very positive effects (e.g. donating to the FHI), creating a very high-return on well targeted donations.
You can see a great review of the overall debate about how large typical differences in cost-effectiveness are here: http://reducing-suffering.org/why-charities-dont-differ-astronomically-in-cost-effectiveness/