What Drives Physician Efficiency? Evidence from Emergency Department Operations

Emergency Departments (EDs) play a critical role in healthcare, serving as the frontline of acute care delivery. However, increasing demand, constrained resources, and the complexity of patient cases pose significant challenges to maintaining operational efficiency. This study investigates the determinants of ED physician efficiency using a robust multi-stage analytical framework. First, we apply Data Envelopment Analysis (DEA) to quantify individual physician efficiency using data from 110,325 patient visits at a leading U.S. hospital. DEA provides a transparent input-output evaluation method, yielding data-driven efficiency scores that reflect physician practice patterns and offer actionable insights for hospital administrators. Second, we apply a Tobit regression model to analyze how various factors—including physician experience, shift familiarity, and patient severity—influence physician efficiency. Third, we conduct comprehensive robustness checks, including instrumental variable analyses and machine learning-based classification tests, to mitigate concerns regarding endogeneity and potential model specification