Bill and Melinda Gates wrote a letter to Warren Buffett about the best deals in philanthropy

Bill and Melinda Gates addressed their traditional annual public letter this year to Warren Buffett, the legendary investor and longtime friend of the couple who in 2006 committed to donating most of his wealth to the Gates Foundation. The Berkshire Hathaway chairman’s gift was valued at more than $30 billion at the time, and brought together the fortunes of the world’s two richest men in a common philanthropic effort.