For the world’s richest man, charity begins — and stays — at home. Amazon founder and CEO Jeff Bezos has given only a tiny fraction of his $160 billion fortune to philanthropic causes, falling far behind fellow billionaires such as Bill and Melinda Gates and former New York mayor Michael Bloomberg, public records show. Although Bezos, 55, and his estranged wife MacKenzie recently pledged $2 billion to a new charitable initiative, their previous giving amounts to a total of just over $145 million or .0906 percent — far less than one percent — of their net worth. Out of $100,000,...