Oklahoma is one of 16 states electing to use an A-F letter grade as an indicator of school quality. On the surface, letter grades are an attractive policy instrument for school improvement; they are seemingly clear, simple, and easy to interpret. Evidence, however, on the use of letter grades as an instrument to rank and improve schools is scant…

President Obama and others have demonstrated considerable interest in the Tulsa school-based pre-K program, one of a handful of universal pre-K programs in the U.S. The short-term effects of high-quality pre-K on school readiness are now well-established. At the same time, questions have been raised as to whether these effects persist over time.…