Differences in teacher quality are commonly cited as a key determinant of the huge international student performance gaps. However, convincing evidence on this relationship is still lacking, in part because it is unclear how to measure teacher quality consistently across countries. We use unique...

Differences in teacher quality are commonly cited as a key determinant of the huge international student performance gaps. However, convincing evidence on this relationship is still lacking, in part because it is unclear how to measure teacher quality consistently across countries. We use unique...

We study an intensive math instruction policy that assigned low-skilled 9th graders to an algebra course that doubled instructional time, altered peer composition and emphasized problem solving skills. A regression discontinuity design shows substantial positive impacts of double-dose algebra on...