Does a high regional concentration of immigrants of the same ethnicity affect immigrant children's acquisition of host-country language skills and educational attainment? We exploit the exogenous placement of guest workers from five ethnicities across German regions during the 1960s and 1970s in...

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...