Injury, Workload, and the Strategic Response of Coaches in the NBA

Worker effort increases contemporaneous output but may result in injury or burnout. Directing effort away from the workers most exposed to injury would reduce this risk, but information on the exposure is often hidden. We ask whether managers act on such private information, studying the NBA as a data-rich workplace. Instrumenting workload with teammate absence, we find that work causally raises injury risk, which contrasts with the spurious negative correlation commonly found in sports medicine studies. We also show that coaches rest players in response to injury risk shocks. By acting on this private information, coaches can raise player productivity.