We build a model where firm size is a source of labor market power. The key mechanism is that a granular employer can eliminate its own vacancies from a worker's outside option in the wage bargain. Hence, a granular employer does not compete with itself. We show how wages depend on employment...

We study whether reallocating existing teachers across schools within a district can increase student achievement, and what policies would help achieve these gains. Using a model of multi-dimensional value-added, we find meaningful achievement gains from reallocating teachers within a district....