Five years ago Warren Buffett pledged to give $31 billion of his $44 billion fortune to the Bill & Melinda Gates Foundation. The pledge gets paid in installments that total $1.7 billion annually, on average. To date, he has already made good on $8.1 billion. The Foundation says that Buffett “wants us to accelerate and deepen our work on the tough issues we’re working to solve.” Translation: The funds will be spent on causes like global development and global health.