Isaiah Andrews wins the John Bates Clark Medal

ECONOMISTS LIKE to crunch numbers and build models to guide policymakers. But who guides them in turn? Isaiah Andrews of Harvard University has been trying to help. On April 20th the American Economic Association awarded him the John Bates Clark Medal, a prize for leading economists under the age of 40, for his efforts.Mr Andrews did not expect to become an econometrician (an economist who specialises in statistics). But during graduate study he was drawn towards questions about the lessons and limits of data. With Matthew Gentzkow of Stanford University and Jesse Shapiro of Brown University, he suggested a way to assess the quality of economists’ models. He also showed economists how to work out how much their findings might change under alternative assumptions, helping them fend off accusations that their results were a feature of their assumptions rather than the data.