July 1, 2010; Source: Seattle Times | Because Berkshire Hathaway stock has increased in value over the past year, Warren Buffett’s 2010 payment on its pledge to the Gates Foundation has gone up by 30% over last year, ringing in at a resounding $1.62 billion. On Friday of last week, the Wall Street Journal estimated the worth of Buffett’s overall pledge to the Gates Foundation at $39 billion. For more on a related story see Buzz Schmidt’s recent article on the subject of Billionaire philanthropy.—Ruth McCambridge