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...

Student performance differs greatly across countries, but little is known about the role of teacher quality in explaining these differences. New international data from the PIAAC survey of adult skills allow for the first time to quantify teacher skills in numeracy and literacy, providing...