The estimates of lives saved, deworming treatments provided, and cash transfers given (we'll refer to these as "impact estimates") are based on:
- The most conservative estimate of the cost per life saved ($5,000) by donating to the four organizations we recommend for life-saving outcomes (or to the Maximum Impact Fund, which was allocated exclusively to life-saving programs in 2020). Read more here about how we calculate the cost of saving a life.
- An average cost per deworming treatment of $0.97. We use our impact calculator to estimate the increase in earnings.
- A rate of one $1,000 cash transfer received by one household for every $1,205 donated to GiveDirectly.
The source for these impact estimates is here. You can learn more by using our impact calculator here. For simplicity, we did not calculate the impact of all donations to GiveWell in 2020. Specifically, the impact estimates do not include:
- Donations made to our standout charities.
- $1.4 million in "Other" donations, a catch-all category that includes approximately $0.8 million in GiveWell Incubation Grants from anonymous donors as well as other one-off support that GiveWell processed.
- $44 million in unrestricted donations we received, of which we expect to allocate a large proportion to our recommended organizations. Because that allocation has not yet been made, we do not calculate its estimated impact here.
The above donations are included in the headline "donations to GiveWell" figure, even though we do not include them in our impact estimates.
 It also includes $1.4 million in "Other" donations. See footnote 1 for information on what's included in "Other."
 Several organizations accept donations for GiveWell and our recommended organizations, including EA Funds, Effective Altruism Foundation, Effective Altruism Australia, RC Forward, Founders Pledge, One for the World, Stiftelsen Effekt, effektiv-spenden.org, and various other effective altruism organizations. We expect to incorporate donations from these organizations in our final accounting of the money we influenced in 2020.
 There is an exception: approximately $0.8 million in GiveWell Incubation Grant funding is included in the "donations to GiveWell" total.
 In 2020, Open Philanthropy made some donations to GiveWell, which are included in the total: $2.4 million in unrestricted funding and $50,000 each for our standout charities Development Media International and the Iodine Global Network. The rest of its support for our top and standout charities, $91.8 million in total, is excluded.
 See our GiveWell Metrics Report – 2019 Annual Review for complete details. The $155 million total excludes GiveWell Incubation Grant funding. Our calculation follows:
- From the "Headline money moved" figure on p. 2 ($152,012,323), we subtract $13,960,512 in GiveWell Incubation Grants, resulting in $138,051,811.
- We add $16,968,150 in 2019 unrestricted funding (p. 10).
- $138.1 million + $17.0 million = $155.1 million.
 The 2020 figure in this chart includes $2.5 million in donations from Open Philanthropy (see footnote 5) as well as Incubation Grants totaling approximately $0.8 million.
 Most importantly, donors were allowed to deduct up to 100% of their adjusted gross income for donations, up from 60% prior to the CARES Act. Donors were not allowed to take deductions above 60% for donations made to donor-advised funds, which don't have to be granted immediately. As a result, donors who wished to exhaust their 100% limit needed to donate directly to a charitable organization. This policy has been extended to 2021.
See this article for a summary of the CARES Act's provisions related to charitable giving:
"On December 27, the U.S. Government enacted a second stimulus package in response to the COVID-19 pandemic, attaching it to a year-end spending bill. The new stimulus package extends many of the charitable giving provisions outlined in the original Coronavirus Aid, Relief, and Economic Security (CARES) Act signed into law in late March of 2020…. Donors who itemize their deductions can now give more cash to charity before reaching their adjusted gross income (AGI) limitation. Formerly set at 60%, the limitation for cash contributions to certain public charities has now been raised to 100% of an individual’s AGI for both 2020 and 2021…. This provision excludes giving to private nonoperating foundations and supporting organizations, along with any contributions made to establish or maintain donor-advised funds (DAFs) like those held at Vanguard Charitable. This means that Vanguard Charitable donors who exhaust the 60% limit with cash contributions to their DAFs in 2020 or 2021 could make any additional donations outside their DAF and have those donations qualify for a deduction (up until reaching the 100% limit)."