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...

Even though some countries track students into differing-ability schools by age 10, others keep their entire secondary-school system comprehensive. To estimate the effects of such institutional differences in the face of country heterogeneity, we employ an international...

We employ a combination of school fixed effects and IV estimation to estimate the effect of class size on student performance in 18 countries. Using the random part of the class-size variation between two adjacent grades within individual schools allows us to identify causal class-size effects....