The time that children spend in school varies across countries. Do these differences explain international gaps in pupils' academic achievements? In this paper, I estimate the effects of instructional time on students' achievement using PISA 2006 data, which includes data samples from over 50...

The literature on class size yields a number of findings. First, class size effects are difficult to find except when using data where class size variations are truly exogenous. Second, Catholic schools have large classes and better performance. Third, to the extent that class size matters, it...