Abstract:  How does teamwork increase productivity? Considering teamwork as joint monitoring and management, I investigate this question by studying the same emergency physicians working in two organizational systems differing in the team-management of work: Physicians are assigned patients in a "nurse-managed" system but divide patients between themselves in a "self-managed" system. The self-managed system increases throughput productivity by reducing a "foot-dragging" moral hazard, in which physicians prolong patient stays with expected future work. I find evidence that physicians in the same location have better information about each other and that, in the self-managed system, they use this information to assign patients.