Thanks for the clarifications, Michael, especially on non-reporters and non-response bias!
On base rates, my prior is that people who self select into GWWC pledges are naturally altruistic and so it’s right (as GWWC does) to use the more conservative estimate—but against this is a concern that self-reported counterfactual donation isn’t that accurate.
It’s really great that GWWC noted the issue of social desirability bias, but I suspect it works to overestimate counterfactual giving tendencies (rather than overestimating GWWC’s impact), since the desire to look generous almost certainly outweighs the desire to please GWWC (see research on donor overreporting: https://​​researchportal.bath.ac.uk/​​en/​​publications/​​dealing-with-social-desirability-bias-an-application-to-charitabl). I don’t have a good solution to this, insofar as standard list experiments aren’t great for dealing with quantification as opposed to yes/​​no answers—would be interested in hearing how your team plans to deal with this!
Thanks for the clarifications, Michael, especially on non-reporters and non-response bias!
On base rates, my prior is that people who self select into GWWC pledges are naturally altruistic and so it’s right (as GWWC does) to use the more conservative estimate—but against this is a concern that self-reported counterfactual donation isn’t that accurate.
It’s really great that GWWC noted the issue of social desirability bias, but I suspect it works to overestimate counterfactual giving tendencies (rather than overestimating GWWC’s impact), since the desire to look generous almost certainly outweighs the desire to please GWWC (see research on donor overreporting: https://​​researchportal.bath.ac.uk/​​en/​​publications/​​dealing-with-social-desirability-bias-an-application-to-charitabl). I don’t have a good solution to this, insofar as standard list experiments aren’t great for dealing with quantification as opposed to yes/​​no answers—would be interested in hearing how your team plans to deal with this!