National Board Certification (NBC) for teachers has become an important innovation in long-standing efforts to improve teacher quality. As states, districts, and teachers increasingly invest resources in this process, information is needed on its cost, impact, and value. This analysis estimates...

Teacher experience has long been a central pillar of teacher workforce policies in U.S. school systems. The underlying assumption behind many of these policies is that experience promotes effectiveness, but is this really the case? What does existing evidence tell us about how, why, and for whom...