Education and early career Karnofsky attended
Stevenson High School in
Lincolnshire, Illinois, and was named a
National Merit Scholar. He graduated from
Harvard University with a degree in
social studies in 2003. At Harvard, he was a member of the
Harvard Lampoon. After graduating, he worked at
Bridgewater Associates, an investment management fund based in
Westport, Connecticut.''''
GiveWell At Bridgewater, Karnofsky met his future GiveWell co-founder
Elie Hassenfeld. In 2006, Karnofsky and Hassenfeld started a charity club where they and other Bridgewater employees pooled in money and investigated the best charities to donate the money to. In mid-2007, with donations from their colleagues, Karnofsky and Hassenfeld formed a fund called "The Clear Fund", and quit their jobs to work full time on
GiveWell, whose goal was to allocate the money in the Clear Fund to the best charities. Under Karnofsky's leadership, the annual money moved to GiveWell-recommended charities increased from $1.6 million in 2010 to $110 million in 2015. Until 2023, he was vice chair of its board of directors.
Astroturfing incident In December 2007, Karnofsky was discovered posting a question about the organization to
MetaFilter using another individual's name, and then posting an answer about GiveWell with his own name but without disclosing his affiliation with GiveWell. The negative publicity led Karnofsky to resign from the role of executive director, though he was later reinstated. The board cut $5000 from his salary to pay for a professional development course he would be required to take. The incident had negative repercussions on GiveWell's reputation. Karnofsky's claim that the incident had been due to sleep deprivation and offer to donate to MetaFilter were mocked by users of the site.
Open Philanthropy Karnofsky was CEO and then co-chief executive officer of
Open Philanthropy, a research and grantmaking foundation whose main funders are
Cari Tuna and
Dustin Moskovitz. Open Philanthropy is an outgrowth of GiveWell Labs, a collaboration of GiveWell and Good Ventures for more speculative giving. As of August 2019, Open Philanthropy has made around 650 grants to over 370 unique organizations, disbursing a total of $857 million. In 2023, Karnofsky first took a leave of absence from his co-CEO role and then moved to a new role as Director of AI Strategy to focus on
AI safety. In 2024, he became a Visiting Scholar at the
Carnegie Endowment for International Peace. As of January 2025, he had left Carnegie.
Anthropic Karnofsky joined Anthropic in January 2025 as member of the technical staff, working on Anthropic's responsible scaling policies (a set of protocols to manage risks associated with increasingly powerful AI models) and other safety planning aspects.
Other activities Karnofsky was on the board of directors of
OpenAI between 2017 and 2021. ==Personal life==