Bill & Melinda Gates Foundation set conditions so that these contributions do not simply increase the foundation's endowment, but effectively work as a matching contribution, doubling the foundation's annual giving. Bloomberg News noted, "Buffett's gift came with three conditions for the Bill & Melinda Gates Foundation: Bill or Melinda Gates must be alive and active in its administration; it must continue to qualify as a charity; and each year it must give away an amount equal to the previous year's Berkshire gift, plus an additional amount equal to 5 percent of net assets. Buffett gave the foundation two years to abide by the third requirement."
Bill & Melinda Gates Foundation principal officers include Co-Chair William H. Gates, Sr. and Chief Executive Officer Susan Desmond-Hellmann. It had an endowment of $50.7 billion . The scale of the foundation and the way it seeks to apply business techniques to giving makes it one of the leaders in venture philanthropy, though the foundation itself notes that the philanthropic role has limitations. In 2007, its founders were ranked as the second most generous philanthropists in the US, and Warren Buffett the first. As of May 16, 2013, Bill Gates had donated $28 billion to the foundation. Since its founding, the foundation has endowed and