This research report and accompanying brief from the RAND Corporation and the Wallace Foundation provides a list of principal pipeline activities and estimates of resources and expenditures for individual activities. This cost study focuses on four main components that districts can consider as they work to improve their own principal pipelines: (1) leader standards, (2) preservice preparation, (3) selective hiring and placement, and (4) on-the-job support and evaluation. The authors note that while districts might not be able to invest in all pipeline activities, this information can help them focus on activities that make sense in their context.