" This approach is now the focus of a crusading group of economists who have transformed international development over the last decade. They do not come up with grand designs; rather, they look for small advantages. As Esther Duflo, the French-born economist who is at the forefront of this approach, put it: “If we don’t know if we are doing any good, we are not any better than the medieval doctors and their leeches. Sometimes the patient gets better; sometimes the patient dies. Is it the leeches or something else? We don’t know.”6 "

― Matthew Syed , Black Box Thinking: Why Some People Never Learn from Their Mistakes - But Some Do