Shaun Ley speaks to the Nobel Prize winning economist Esther Duflo. The experimental trails she ran with two colleagues in Africa and India produced some surprising results. Among their findings: food aid isn’t helping the poor, and the poorest kids don’t need more books, they need more time. A fashionable idea wins the Nobel Prize. But is this really a story of failure of economists to predict the financial crisis, and of economics to offer big solutions?