Students in some countries do far better on international achievement tests than students in other countries. Is this all due to differences in what students bring with them to school - socio-economic background, cultural factors, and the like? Or do school systems make a difference? This essay...

We provide evidence that the robust association between cognitive skills and economic growth reflects a causal effect of cognitive skills and supports the economic benefits of effective school policy. We develop a new common metric that allows tracking student achievement across countries, over...