GWWC’s 2023–2024 impact evaluation (executive summary)

By Aidan Whitfield🔸, Giving What We Can🔸 @ 2025-06-03T22:05 (+108)

This post presents the executive summary from Giving What We Can’s impact evaluation for the 2023–2024 period. At the end of this post we share links to more information, including the full report and working sheet for this evaluation. We look forward to your questions and comments!

This report estimates Giving What We Can’s (GWWC’s) impact over the 2023–2024 period, expressed in terms of our giving multiplier — the donations GWWC caused to go to highly effective charities per dollar we spent. We also estimate various inputs and related metrics, including the lifetime donations of an average 🔸10% pledger, and the current value attributable to GWWC and its partners for an average 🔸10% Pledge and 🔹Trial Pledge. 

Our best-guess estimate of GWWC’s giving multiplier for 2023–2024 was 6x, implying that for the average $1 we spent on our operations, we caused $6 of value to go to highly effective charities or funds. 

While this is arguably a strong multiplier, readers may wonder why this figure is substantially lower than the giving multiplier estimate in our 2020–2022 evaluation, which was 30x. In short, this mostly reflects slower pledge growth (~40% lower in annualised terms) and increased costs (~2.5x higher in annualised terms) in the 2023–2024 period. The increased costs — and the associated reduction in our giving multiplier — were partly due to one-off costs related to GWWC’s spin-out. They also reflect deliberate investments in growth and the diminishing marginal returns of this spending. We believe the slower pledge growth partly reflects slower growth in the broader effective altruism movement during this period, and in part that GWWC has only started shifting its strategy towards a focus on pledge growth since early 2024. We’ve started seeing some of this pay off in 2024 with about 900 new 🔸10% Pledges compared to about 600 in 2023. 

All in all, as we ramp up our new strategy and our investments start to pay off, we aim and expect to sustain a strong (at least 5x) average and marginal giving multiplier over the coming years, while significantly increasing our pledge growth and overall impact. This reflects that our ultimate goal is not to maximise our multiplier on a small budget, but instead to maximise our impact while spending our operational funds cost-effectively, strategically scaling our impact. Our long-term goal is to reach 1 million pledgers giving $3 billion annually to high-impact charities.

In this evaluation, we also revisited our estimate of the value of an average 🔸10% Pledge. In contrast to our 2020–2022 impact evaluation — which found that the average 🔸10% pledger’s donations remained stable or increased over time, in this evaluation, using new data and a different analytical approach, we now find that average pledge donations fall over time. This is mostly because, over time, the proportion of pledgers who continue to record significant donations falls while the average donations of pledgers who continue donating remain stable. This has caused us to update our estimates of pledge value: 

Our updated best-guess estimate is that the average 🔸10% pledger donates $100K USD^[1] over the course of their pledge (between signing their pledge and retiring). 

After applying various discounts — for time (future donations may be less valuable than present ones), effectiveness (not all donations go to high-impact charities), and counterfactuality (some donations would have occurred without GWWC) — our best guess is that, for each 🔸10% Pledge, GWWC generates, on average, roughly $15K in counterfactual donations for high-impact charities — meaning these donations would not have happened without GWWC.^[2] We emphasise that the changes since 2020–2022 reflect changes in our methodology and available data and not an expectation that pledges acquired in this period produced less value than in 2020–2022. These estimates remain uncertain, and we expect them to change over time — potentially in either direction.

The majority of our impact (roughly 75%) continues to come from our pledge work, with a minority coming from non-pledge donations made through our platform. We also find that the vast majority (>90%) of our pledge impact comes from 🔸10% Pledges, with a minority coming from 🔹Trial Pledges. These results validate the strategic reorientation towards 🔸10% Pledge growth that was informed by our 2020–2022 impact evaluation. They also identify significant room to improve ‘pledge quality’ — that is, the average value generated by a 🔸10% Pledge. In particular, we believe that we should consider focusing more efforts on combatting pledger attrition, as our results show only about 30% of 🔸10% pledgers are recording donations via our platform 5 years after commencing their pledge. This doesn’t necessarily mean these pledgers aren’t fulfilling their pledge — reporting is not a requirement, though it is strongly encouraged. That said, our most recent surveys of pledgers who don’t record their donations didn’t find a meaningful signal that most of these pledgers are, in fact, donating. Thus, these results show a strong case for addressing pledger attrition, an insight that we expect will inform our strategic plans going forward.

Finally, we emphasise that our results are sensitive to the specific approach we used to generate them, which is subject to many assumptions. We recommend that readers interested in learning more about the results read the ‘How to interpret our estimates’ section. Readers interested in specific calculations can refer to the relevant sections of the main report.

Where you can learn more

• Our full impact evaluation report — this includes a much more detailed description of our assumptions, considerations, methodology, and results.
  • More about our giving multiplier
  • More about the value of our pledges
• Our working sheet, where we combine our inputs to calculate our results.
• Our survey documentation, where we provide information about all the surveys we conducted as part of this impact evaluation.
• Our donation classification sheet, where we categorised pledge and non-pledge donation recipients to estimate our effectiveness coefficients.
• Our GitHub repository, which contains code we used to analyse the survey results and calculate key inputs (see Appendix H of the main report for links to readable HTML outputs).

1. ^{^}

    All monetary figures provided here are adjusted for inflation to 2024 USD. 

2. ^{^}

   To avoid double-counting impact, our guidance for 2025 is that, for each new pledge, GWWC and our pledge partners attribute themselves $10K per🔸10% Pledge for their work that causes the pledge and GWWC should attribute $5K (over the lifetime of the pledge) for ongoing ‘pledge stewardship’ work.