The project also investigated teachers’ compensating wage differentials—the average salary premium (or penalty) teachers earn based on their assignments and school contexts (available as an Annenberg working paper). Theoretically, hard-to-staff positions, like those in STEM fields or in high-need settings, should command higher salaries. Yet common practices in the K-12 teacher labor market, including the widespread use of single salary schedules for all teachers, are expected to limit the responsiveness of teachers’ earnings to labor market pressures.