TOKYO -- Hans Rosling, the late Swedish statistician, had a magician's eye for presenting numbers. One of his most striking performances can be seen in a 2010 video called "200 Countries, 200 Years, 4 Minutes." It has been watched 10 million times on the BBC's YouTube channel.
In the clip, Rosling conjures an animated graph on which colored bubbles show average incomes and life expectancies in the nations of the world. As a counter ticks toward the 21st century, many of the circles rise up the screen, with Asian states prominent after World War II. It is a powerful demonstration of how humanity has grown better off than ever before -- at least according to the measures Rosling chose.