Billionaires back antismoking effort

Bill Gates and New York City Mayor Michael R. Bloomberg have announced that they would spend $500 million to stop people around the world from smoking. The World Health Organization estimates that tobacco will kill up to a billion people in the 21st century. In an effort to cut that number, Bloomberg's foundation plans to commit $250 million over four years on top of a $125 million gift he announced two years ago, while the Bill and Melinda Gates Foundation is allocating $125 million over five years.