The future shape of evaluation systems will be determined by who bears the cost of controlling the quality of the teacher workforce. Until now, teachers and students have largely born these costs. But if states and districts are serious about improving workforce quality, they must take on a greater share. Consequently, the current orientation of input- and output-based evaluations will be supplemented with more rigorous process-based evaluation. Heightened cost pressures for school leadership will likely lead to more automated, data-driven evaluation systems.