scores in terms of a student's position in a widening distribution of knowledge. If a standard deviation in test scores in … later grades translates into a larger difference in knowledge, an intervention's effect on normalized test scores may fall … even as its effect on knowledge does not. We evaluate this hypothesis by fitting a model of education production to …

, this paper proposes a methodology to assess the effect of teacher subject content knowledge on student learning when panel …'s teachers, and knowledge of the correlation structure of teacher knowledge across time and grades, allow estimating two … structural parameters of interest: the contemporaneous effect of teacher content knowledge, and the extent of fade out of teacher …