Do Physicians Influence Each Other’s Performance? Evidence from the Emergency Department

Understanding potential ways through which physicians impact each other's performance can yield new insights into better management of hospitals' operations. We use evidence from Emergency Medicine to study whether and how physicians who work alongside each other during same shifts affect each other's performance. We find strong empirical evidence that physicians affect each other's speed and quality, and scheduling diverse peers during the same shift could have a positive net impact on the operations of a hospital Emergency Department (ED). Specifically, our results show that a faster (slower) peer decreases (increases) the average speed of a focal physician compared to a same-speed peer. Similarly, a higher- (lower-) quality peer decreases (increases) a focal physician's average quality. Furthermore, the presence of a less-experienced peer improves a focal physician's average speed. However, in contrast to the conventional wisdom, we do not find any evidence that more-experienced physicians can affect the performance of their less-experienced peers. We investigate various mechanisms that might be the driving force behind our findings, including psychological channels such as learning, social influence, and homophily as well as resource spillover. We identify resource spillover as the main driver of the effects we observe and show that, under high ED volumes (i.e., when the shared resources are most constrained), the magnitude of the observed effects increases. While some of these observed effects tend to be long-lived, we find that their magnitudes are fairly heterogeneous among physicians. In particular, our results show that newly-hired and/or high-performing physicians are typically more influenced than others by their peers. Finally, we draw conclusions from our results and discuss how they can be utilized by hospital administrators to improve the overall performance of physicians via better scheduling patterns and/or training programs that require physicians to work during same shifts.