We estimate peer effects for fourth graders in six European countries. The identification relies on variation across classes within schools. We argue that classes within primary schools are formed roughly randomly with respect to family background. Similar to previous studies, we find sizeable...

If students tend to choose instructors with high teaching ability, a negative link between class size and student performance may remain obscured until this kind of sorting has been taken into account. Using data from student evaluation surveys, we confirm that it is crucial to control for...