We think it is important that people choose where to donate based on how they can help others the most. Therefore, in order to know whether Giving What We Can is a good target for donations, we need to know the impact of our activities. In order to help people to donate to the charities they believe are the most effective, we’ve described our attempts at quantifying our impact. We’ve also provided a spreadsheet so that you can make the same calculation using your own assumptions.
We measure our impact in terms of how many dollars we move to highly effective charities. We need to be moving more than $1 to effective charities (which wouldn’t otherwise be donated) for every $1 given to us, otherwise it would be better to donate directly to those charities. Measuring impact is difficult and uncertain, so we have given a range of estimates, using different methods and assumptions. That range is between $6 and $300 to top charities for every $1 donated to Giving What We Can.
We measure our effectiveness using the amount of money we’ve caused to be donated to highly effective charities. We’ve set out detailed calculations, so you can see how we arrive at our estimates.
We’ve provided both a low, very conservative estimate, a higher, more realistic scenario, and an optimistic marginal impact calculation. We believe that, even at the lowest estimate of our effectiveness, Giving What We Can represents an excellent return on investment, and that you can be confident that a donation to us will have as much positive impact as possible.
You can read about these calculations in more detail in our latest Fundraising Prospectus.
You can also read about our Spring 2015 fundraiser.
We have also provided the spreadsheet used to calculate the Realistic estimate if you would like to try out the calculation using your own assumptions.
Lower bound — 6 : 1
The lower bound calculation uses more conservative or pessimistic assumptions, and counts only the money that we know we have actually moved to charity (as opposed to what people have pledged to donate in future). We think that this represents the worst-case scenario for our impact.
Under this scenario, for every $1 spent by Giving What We Can, around $6 is moved to top charities.
Read our detailed lower bound impact calculation in our latest Fundraising Prospectus.
Realistic — 60 : 1
The realistic scenario uses detailed information about what we expect members to pledge into the future, and provides what we consider to be the most realistic estimate of our effectiveness.
Under this scenario, for every $1 spent by Giving What We Can, around $60 is moved to top charities.
Read our detailed realistic impact calculation in our latest Fundraising Prospectus.
As with any modelling effort, this calculation makes certain assumptions about which figures to use. If you believe that using different assumptions would lead to a more accurate estimate of our effectiveness, you can use our spreadsheet to test them out:
Click here to open the Realistic calculation as a Google Spreadsheet. Once it loads, click 'File' -> 'Make a copy' to create a version you can edit (you will need to be signed into your Google account).
Optimistic — 90-300 : 1
The optimistic calculation tries to find our marginal impact – that is, what is the cost of signing up another member, compared what we expect that member to contribute over their lifetime.
This calculation considers a range of scenarios, and (while it is perhaps more speculative than the other two calcultions) suggests that it is plausible that for every $1 spent by Giving What We Can, somewhere between $90 and $300 is moved to top charities.
Read our detailed optimistic impact calculation in our latest Fundraising Prospectus.