Robert Chambers. Photo by Alex Harris.

There’s one word that cries out for a red pencil in Nicholas Kristof’s otherwise excellent Sunday column about social entrepreneurs, ”The Age of Ambition.”

“Young.”

Bill Gates. AP Photo by Peter Dejong

Bill Gates got headlines this week with his call for corporations to adopt a new form of “creative capitalism” in a speech at the World Economic Forum in Davos, Switzerland. But he also issued a more personal call to action, made more credible by his own career shift to devote his full time to the Gates’ foundation work on global health, poverty and education.

“The passing of time requires each of us to take stock,” Gates said. “What have I accomplished so far? And what do I still want to accomplish?”