Do sustained, structured professional learning communities improve student achievement? Longitudinal evidence from Texas public schools

Districts invest substantial instructional time and staffing capacity in professional learning communities (PLCs) to strengthen instruction, yet rigorous evidence on whether PLCs improve student achievement is inconclusive. This study estimates the achievement effects of the PLC at Work® process in Texas public schools by leveraging variation in the timing of Solution Tree’s Model PLC at Work® designation as an externally observable indicator of sustained, routinized PLC implementation. Using statewide longitudinal administrative data and Texas STAAR mathematics and reading outcomes for students in grades 4-7, we employ a staggered difference-in-differences design to estimate dynamic impacts by years relative to designation. Post-designation impacts are positive and strengthen over time in both subjects. Findings suggest that PLC implementation functions as a multi-year improvement system rather than a short-cycle interaction and that measurable achievement gains may accrue as structured collaborative routines stabilize over time.