Physician Group Influences on Treatment Intensity and Health: Evidence from Physician Switchers
利用医生在同一医院内换组的数据，研究发现加入治疗强度更高的医生组会立即提升医生自身的治疗强度，但未发现患者健康结果改善，表明群体效应可能不具生产力。
Treatment intensity varies remarkably across physicians, and physicians are increasingly working in groups. This paper tests whether group affiliation impacts physicians’ treatment intensity and patient health. Using Medicare inpatient claims data, we focus on internists who switch groups within the same hospital. Event studies show that internists who join more-intensive groups immediately increase their own intensity, with an elasticity of 0.27. This change is reflected in higher Medicare spending due to higher-priced services. We do not detect a change in health outcomes, suggesting that treatment intensity induced by group affiliation may not be productive.