We estimate that GWWC’s marginal 2025 giving multiplier is around 14x
I think it would be really helpful to graph this over time. If the majority of it manifests in 10 years, that’s very different than e.g. if it assumes pledgers’ will be young, have increasing salaries over their careers, and give the majority of it in 40-50 years time.
(and AI doomers will probably think that even 10 years is an irrelevant timespan, and it only really matters how much is moved in the next 1-5 years)
I don’t have the estimates for how the multiplier changes over time, though you would expect a decline, driven by the future pledging pool being less EA/zealous than earlier batches.
For the value of a *pledge* - based on analysis of the available data, it doesn’t appear that donations increase over time (for any given pledge batch), so after relevant temporal discounts (inflation etc), the value of a pledge is relatively front-loaded:
To be clear, I don’t mean ‘graph of how the expected multiplier on a dollar changes over time’, I mean ‘graph of how the expected donations generated by a dollar given are distributed over time’ (before any discounting).
This is something Sjir’s team and myself have discussed at length—we’re definitely more pessimistic than GWWC on this point.
CEARCH’s view is that the raw numbers look good, but if you regress dollar donated against year since pledging, while controlling for pledge batch (and hence the risk that earlier pledgers are systematically different/more altruistic), there is a positive but statistically insignificant relationship between average annual donations and years since pledging (n.b. increase in 35 dollars per annum at p=0.8). The experts we spoke to were split, with a weak lean towards it increasing over time—some were convinced by the income effects, while others were sceptical that you can beat attrition.
Ultimately, we chose to model a very marginal increase (<0.01% per annum); we’re really not confident that you can reasonably expect an increase in giving over time for the 2025 and future pledge batches.
For how expected donations generated by a dollar evolves over time (ignoring discounts), available evidence suggests that it’s flat (and so the graph is just a horizontal line terminating around 30 years later). There’s a lot of uncertainty, not least on how long the giving lasts, given that we can only observe a little more than a decade of giving at this point.
Seconding this! I would also be very curious about what the multiplier is if you discount giving in future years, ideally as a chart of multiplier vs annual discount rate.
I haven’t looked at this model, but in GWWC’s 2020–2022 Impact evaluation, you can change the annual discount rate here or here (and other key parameters in cells nearby)
If I understand correctly, a ~10% yearly discount rate ~halves the expected value of a pledge and changes the best guess non-marginal multiplier from 30x to 23x
I think the equivalent in this model is here and a ~10% discount rate changes the marginal multiplier from 14x to 8x
I think it would be really helpful to graph this over time. If the majority of it manifests in 10 years, that’s very different than e.g. if it assumes pledgers’ will be young, have increasing salaries over their careers, and give the majority of it in 40-50 years time.
(and AI doomers will probably think that even 10 years is an irrelevant timespan, and it only really matters how much is moved in the next 1-5 years)
I don’t have the estimates for how the multiplier changes over time, though you would expect a decline, driven by the future pledging pool being less EA/zealous than earlier batches.
For the value of a *pledge* - based on analysis of the available data, it doesn’t appear that donations increase over time (for any given pledge batch), so after relevant temporal discounts (inflation etc), the value of a pledge is relatively front-loaded:
To be clear, I don’t mean ‘graph of how the expected multiplier on a dollar changes over time’, I mean ‘graph of how the expected donations generated by a dollar given are distributed over time’ (before any discounting).
You may be interested in this chart from the What trends do we see in GWWC Pledgers’ giving? subsection of GWWC’s 2020-22 cost-eff self-evaluation, as well as their discussion:
This is something Sjir’s team and myself have discussed at length—we’re definitely more pessimistic than GWWC on this point.
CEARCH’s view is that the raw numbers look good, but if you regress dollar donated against year since pledging, while controlling for pledge batch (and hence the risk that earlier pledgers are systematically different/more altruistic), there is a positive but statistically insignificant relationship between average annual donations and years since pledging (n.b. increase in 35 dollars per annum at p=0.8). The experts we spoke to were split, with a weak lean towards it increasing over time—some were convinced by the income effects, while others were sceptical that you can beat attrition.
Ultimately, we chose to model a very marginal increase (<0.01% per annum); we’re really not confident that you can reasonably expect an increase in giving over time for the 2025 and future pledge batches.
For how expected donations generated by a dollar evolves over time (ignoring discounts), available evidence suggests that it’s flat (and so the graph is just a horizontal line terminating around 30 years later). There’s a lot of uncertainty, not least on how long the giving lasts, given that we can only observe a little more than a decade of giving at this point.
Seconding this! I would also be very curious about what the multiplier is if you discount giving in future years, ideally as a chart of multiplier vs annual discount rate.
I haven’t looked at this model, but in GWWC’s 2020–2022 Impact evaluation, you can change the annual discount rate here or here (and other key parameters in cells nearby)
If I understand correctly, a ~10% yearly discount rate ~halves the expected value of a pledge and changes the best guess non-marginal multiplier from 30x to 23x
I think the equivalent in this model is here and a ~10% discount rate changes the marginal multiplier from 14x to 8x