If Buffet or Barkley or whoever wants to pay more, please ask them why they are not voluntarily doing so right now.
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Charity biography
The world’s second richest man continues to make his fortune in investment and turn it to philanthropy in the grand tradition of Carnegie and Rockefeller. In 2006 he made American history by making the largest ever charitable donation by an individual – $37bn to the Bill and Melinda Gates Foundation.
Additionally, I saw an interview with an IRS representative who said there are people who give large sums, anonymously to the IRS (seriously!). I think it’s highly probably that Mr. Buffett would be one of those people.