Former New York City Mayor Michael Bloomberg speaks on behalf of Bloomberg Philanthropies Aug. 5 during the U.S.-Africa Business Forum. Bloomberg had been expected to commit most of his post-mayoral time to his charitable work, but said he found the day-to-day dealings at his media company to be too intriguing to stay away. Saul Loeb/AFP/Getty Images hide caption

itoggle caption Saul Loeb/AFP/Getty Images

New York Mayor Michael Bloomberg speaks during a press conference in London in September. Matt Dunham/AP hide caption

itoggle caption Matt Dunham/AP