The collapse of Madonna’s high-profile effort to build a school for impoverished girls in Malawi has made headlines around the world. The singer’s celebrity and the $3.8 million lost in the effort guaranteed that. But in philanthropy, failure is an almost everyday occurrence. Giving money away smartly, so that it not only gets results but also gets more and better results over time, is excruciatingly hard. Not for nothing are many social problems called “intractable.”