Microfinance as a tool to fight poverty and the effort to recognize and stem global warming have both become movements. But as Yasmina Zaidman, at the Acumen Fund, told me, both problems (and their solutions!) were recognized more than thirty years ago. We weren’t lacking the answer—Muhammad Yunus had it all along. So why did it take thirty years for the idea to gain steam? The answer, as you’ve probably guessed, is that there’s a difference between telling people what to do and inciting a movement.
