And while natural resources are exhaustible - the more you use the less you have - knowledge is a growing resource - the more you use the more you have. The scientific discovery that had the largest impact on human development was the discovery of ignorance, and learning as the means to advance knowledge. As New York Times columnist Thomas Friedman put it, PISA and oil don't mix easily.2 Israel is not alone in outperforming its oil-rich neighbours by a large margin when it comes to learning outcomes at school: most of the highest-performing education systems are poor in natural resources.