Hi Vasco, thanks for your response! Sorry for my delay in getting back to you, I have just got back from leave. I have tried to leave responses to your main points below, but if I have missed anything please let me know.
Re: our marginal multiplier: This is not something we have explicitly tried to model. The most relevant information I can provide here is that our bar for undertaking new pledge acquisition activities is that they must at least exceed 5x in expectation, but this is still not the same as our marginal multiplier for a number of reasons. While we hope to publish an estimate of our average multiplier for 2025 in early 2026, I currently don’t expect to try to explicitly estimate our marginal multiplier. One key reason for this is that, unless we have identified a very scalable method for growing pledges, our marginal multiplier estimate would change quite quickly as we receive more funding and so may only be relevant for a brief period.
Re: how we report the number of pledgers on the website: Thanks for sharing your thoughts here! I continue to think that the statement on our website is accurate and that it isn’t misleading to use the terms ‘community’ and ‘pledging’ here. Simply, these are the numbers of people in our community who have taken pledges with GWWC. I don’t believe the text makes a claim about the number of pledgers who are reporting their donations (which is not a requirement of the pledge) or the number who are fulfilling their pledge (which we don’t have a reliable estimate of). It isn’t clear to me why we should think that the median person who reads the statement would assume that 90% of pledgers are donating.
Re: modelling pledge value for different cohorts: This kind of regression modelling will be something we continue to consider implementing in future evaluations, but currently it isn’t clear enough to me that these models will be better predictors of future cohort pledge donations than the ‘average of recent years’ method we currently use. The trends to date have simply been too noisy for me to feel confident in any given mathematical model. I also think these models involve some tradeoffs in terms of time investment and legibility and that we also need to factor in these considerations when selecting our approach.
Re: Trial Pledges: We have not estimated the fraction of impact we attribute to the 🔸10% Pledge that was caused by the 🔹Trial Pledge, but I would roughly guess for recent cohorts it is somewhere in the vicinity of 5–20%. It is difficult to come up with a precise estimate because we don’t know how causally responsible the 🔹Trial Pledge is for the 🔸10% Pledge in these cases (as you note).
While we hope to publish an estimate of our average multiplier for 2025 in early 2026
Great to know!
I currently don’t expect to try to explicitly estimate our marginal multiplier. One key reason for this is that, unless we have identified a very scalable method for growing pledges, our marginal multiplier estimate would change quite quickly as we receive more funding and so may only be relevant for a brief period.
I think estimating in early 2026 GWWC’s marginal multiplier in 2025 would still be useful. A value higher than 1 would suggest GWWC should have received more funding this year.
The marginal multiplier should ideally not vary much across years. GWWC should move funds from the years with the lowest marginal multiplier to the years with the highest marginal multiplier until the marginal multiplier is the same across all years. If you estimated your marginal multiplier annually, you could realise you should have spent more/​less if you marginal multiplier decreased/​increased.
Hi Vasco, thanks for your response! Sorry for my delay in getting back to you, I have just got back from leave. I have tried to leave responses to your main points below, but if I have missed anything please let me know.
Re: our marginal multiplier: This is not something we have explicitly tried to model. The most relevant information I can provide here is that our bar for undertaking new pledge acquisition activities is that they must at least exceed 5x in expectation, but this is still not the same as our marginal multiplier for a number of reasons. While we hope to publish an estimate of our average multiplier for 2025 in early 2026, I currently don’t expect to try to explicitly estimate our marginal multiplier. One key reason for this is that, unless we have identified a very scalable method for growing pledges, our marginal multiplier estimate would change quite quickly as we receive more funding and so may only be relevant for a brief period.
Re: how we report the number of pledgers on the website: Thanks for sharing your thoughts here! I continue to think that the statement on our website is accurate and that it isn’t misleading to use the terms ‘community’ and ‘pledging’ here. Simply, these are the numbers of people in our community who have taken pledges with GWWC. I don’t believe the text makes a claim about the number of pledgers who are reporting their donations (which is not a requirement of the pledge) or the number who are fulfilling their pledge (which we don’t have a reliable estimate of). It isn’t clear to me why we should think that the median person who reads the statement would assume that 90% of pledgers are donating.
Re: modelling pledge value for different cohorts: This kind of regression modelling will be something we continue to consider implementing in future evaluations, but currently it isn’t clear enough to me that these models will be better predictors of future cohort pledge donations than the ‘average of recent years’ method we currently use. The trends to date have simply been too noisy for me to feel confident in any given mathematical model. I also think these models involve some tradeoffs in terms of time investment and legibility and that we also need to factor in these considerations when selecting our approach.
Re: Trial Pledges: We have not estimated the fraction of impact we attribute to the 🔸10% Pledge that was caused by the 🔹Trial Pledge, but I would roughly guess for recent cohorts it is somewhere in the vicinity of 5–20%. It is difficult to come up with a precise estimate because we don’t know how causally responsible the 🔹Trial Pledge is for the 🔸10% Pledge in these cases (as you note).
Thanks, Aidan!
Great to know!
I think estimating in early 2026 GWWC’s marginal multiplier in 2025 would still be useful. A value higher than 1 would suggest GWWC should have received more funding this year.
The marginal multiplier should ideally not vary much across years. GWWC should move funds from the years with the lowest marginal multiplier to the years with the highest marginal multiplier until the marginal multiplier is the same across all years. If you estimated your marginal multiplier annually, you could realise you should have spent more/​less if you marginal multiplier decreased/​increased.