|Type||501(c)(3) organization, ruling year 2007|
GiveWell is an American non-profit charity assessment and effective altruism-focused organization. GiveWell focuses primarily on the cost-effectiveness of the organizations that it evaluates, rather than traditional metrics such as the percentage of the organization's budget that is spent on overhead.
In 2006 Holden Karnofsky and Elie Hassenfeld, who worked at a hedge fund in Connecticut, formed an informal group with colleagues to evaluate charities based on data and performance metrics similar to those they used at the fund, and were surprised to find the data often didn't exist. The next year, Karnofsky and Hassenfeld formed GiveWell as a nonprofit to provide financial analyst services to donors. They eventually decided to rate charities based on the metric of how much money it cost to save a life. In the first year, funding to run the nonprofit was provided by a fund called the Clear Fund into which the former members of informal club, now directors of GiveWell, had put around $300,000, with about half of that going to fund the organization.
In the first year, Karnofsky and Hassenfeld advocated that charities should generally spend more money on overhead, so that they could pay for staff and record keeping to track how effective their efforts were; this ran counter to standard ways of evaluating charities based on the ratio of overhead to funds deployed for the charity work itself.
In late 2007, GiveWell's founders promoted the organization on several internet blogs and forums using sockpuppets to ask questions about where to find good information about how to donate and then answering them, recommending GiveWell. GiveWell's board of directors investigated and found that the founders Karnofsky and Hassenfeld had acted inappropriately and as a result, it fined each of them $5000 and Karnofsky was demoted from executive director to a program director.
In 2008, GiveWell received funding from the William and Flora Hewlett Foundation's Nonprofit Marketplace Initiative. The Hewlett Foundation continued to be a major funder of GiveWell until March 2014, when the Hewlett Foundation announced that it was ending the Nonprofit Marketplace Initiative based on a 2010 study it commissioned that found that only 3% of donors selected charities based on performance metrics (rather than e.g. loyalty, personal connections, or faith), and a subsequent 2012 study showing that efforts to provide better data were not changing that pattern.
Open Philanthropy Project
In 2011, Good Ventures, founded with $8.3 billion by husband and wife Dustin Moskovitz and Cari Tuna, partnered with GiveWell to set up a partner organization called the Open Philanthropy Project, as a vehicle to direct the funding done by Good Ventures. In 2015, Mike Krieger and his fiancee Kaitlyn Trigger pledged $750,000 to the Open Philanthropy Project over two years, with 10% going to fund the operations of the project.
Open Philanthropy project has investigated giving money to criminal justice reform and a range of other policy areas, and has funded work into mitigating risks of artificial intelligence, biosecurity, and global health.
In 2017, the Open Philanthropy Project separated from GiveWell, and upon Karnofsky stepping down as Co-Executive Director of GiveWell, Elie Hassenfeld became GiveWell's sole Executive Director. 
GiveWell makes annual recommendations of the most cost-effective charities. They estimate that the first four of these save an average of one life for every US$3000–5000 donated. The 2020 top charities are:
Supplements to prevent vitamin A deficiency
- American Institute of Philanthropy
- Earning to give
- Ethics of philanthropy
- Founders Pledge
- Giving What We Can
- Raising for Effective Giving
- Venture philanthropy
- "Clear Fund". Retrieved 4 April 2017.
- Pitney, Nico (March 26, 2015). "That Time A Hedge Funder Quit His Job And Then Raised $60 Million For Charity". Huffington Post. Retrieved April 27, 2015.
The tech community around Silicon Valley has embraced the movement with particular enthusiasm, and GiveWell moved its offices to San Francisco in 2013.
- "Young Duo to 'Clear' the Way for Charitable Giving". National Public Radio.
- Wenar, Leif (2011). "Poverty Is No Pond". In Illingworth, Patricia M. L.; Pogge, Thomas; Wenar, Leif (eds.). Giving Well: The Ethics of Philanthropy. Oxford University Press. p. 124. doi:10.1093/acprof:oso/9780199739073.001.0001. ISBN 978-0-19-973907-3. OCLC 588998863.
- Peter Singer. The Life You Can Save: Acting Now To End World Poverty, Random House, 2009. Ch. 6, pp. 81–104
- Strom, Stephanie (20 December 2007). "2 Young Hedge-Fund Veterans Stir Up the World of Philanthropy". The New York Times.
- Stephanie Strom (8 January 2008). "Founder of a Nonprofit Is Punished by Its Board for Engaging in an Internet Ruse". The New York Times. Retrieved 13 September 2011.
- Strom, Stephanie (15 January 2008). "Nonprofit Punishes a 2nd Founder for Ruse". The New York Times.
- Louie, Lindsay; Twersky, Fay (March 11, 2014). "Strengthening Our Sector". William and Flora Hewlett Foundation. Archived from the original on September 18, 2016. Retrieved September 6, 2014.
- Aizenman, Nurith (November 27, 2017). "On #GivingTuesday, How To Get The Most Bang For Your Charity Buck". NPR.org. NPR. National Public Radio. Retrieved 27 February 2018.
- Preston, Caroline (January 10, 2012). "Another Facebook Co-Founder Gets Philanthropic". Chronicle of Philanthropy. Retrieved March 25, 2014.
- Nicole Bennett; Ashley Carter; Romney Resney & Wendy Woods (February 10, 2016). "bcg.perspectives - How Tech Entrepreneurs Are Disrupting Philanthropy". The Boston Consulting Group. Retrieved September 12, 2017.
- Matthews, Dylan (April 24, 2015). "You have $8 billion. You want to do as much good as possible. What do you do?". Vox. Retrieved April 27, 2015.
- Berkey, Brian. "The Institutional Critique of Effective Altruism" (PDF). Utilitas: 22. Retrieved 12 September 2017.
- Elizabeth Preston (July 1, 2015). "Boston group awards $6m from Elon Musk to jump-start artificial intelligence research". Boston Globe. Retrieved March 20, 2016.
- Jack Clark (July 1, 2015). "Musk-Backed Group Probes Risks Behind Artificial Intelligence". Bloomberg Business. Retrieved March 20, 2016.
- Vanian, Jonathan (July 1, 2015). "Why Elon Musk is donating millions to make artificial intelligence safer". Fortune. Retrieved March 19, 2016.
- Yassif, J (2017). "Reducing Global Catastrophic Biological Risks". Health Security. 15 (4): 329–330. doi:10.1089/hs.2017.0049. PMC 5576261. PMID 28745920.
- "Leverage: Why This Silicon Valley Funder Is Doubling Down on a Beltway Think Tank". Inside Philanthropy. March 9, 2016. Retrieved March 19, 2016.
- "Our Top Charities". GiveWell. Retrieved 2021-03-09.
- Lieber, Ron (April 25, 2014). "Donating, and Making Sure the Money Is Put to Work". New York Times. Retrieved June 4, 2016.
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