availability of data on all teachers and students in North Carolina over a ten-year period allows us to explore them in more detail … effects of changes in class size or to the socio-economics characteristics of students, as measured, for example, by the …

to be matched with more advantaged students, and we measure the bias this pattern generates in estimates of the impacts … restrict the analysis to schools that assign students to classrooms in a manner statistically indistinguishable from random … advantaged students, a finding that may help explain why the observed form of teacher-student matching persists in equilibrium …

assignments but did not write comments on assignments to guide students about weak portions of their responses. Results were … announced late but were communicated to students just after the result declaration. This suggested that all persons involved in …