Making Teaching Last: Long-Run Value-Added

Teacher value-added (VA) measures how teachers improve their students' contemporaneous test scores. Many teachers, however, argue that contemporaneous test scores are a poor proxy for their permanent influence on students. This paper considers a new VA measure -- 'long-run VA' -- that captures teachers' contributions that persist by replacing contemporaneous test scores with subsequent test scores in VA estimation. We find that students assigned to high long-run VA teachers fare substantially better in terms of long-term outcomes. Policy simulations indicate that the use of long-run VA improves policy effectiveness by a factor of two compared to traditional VA measures.