This paper empirically investigates how competition affects physicians’ opportunistic behavior in the context of the utilization of MRI scanners. We examine micro-panel data on Japanese hospitals, where we observe how physicians change their usage of MRI scanners in response to MRI adoption by nearby hospitals. We identify competition-driven physician-induced demand: Hospitals lose patients because of MRI adoption by nearby hospitals, and, to compensate for this loss, physicians perform more MRI scans per patient. Although competition may benefit consumers through better access to MRI scanners, it also causes additional physician-induced demand.

本文实证研究了在使用 MRI 扫描仪的背景下，竞争如何影响医生的机会主义行为。我们检查了日本医院的微面板数据，在那里我们观察医生如何改变他们对 MRI 扫描仪的使用以响应附近医院采用 MRI 的情况。我们确定了由竞争驱动的医生引发的需求：由于附近医院采用 MRI，医院失去了患者，为了弥补这种损失，医生对每位患者进行了更多的 MRI 扫描。尽管竞争可能会通过更好地使用 MRI 扫描仪使消费者受益，但它也会引起医生引发的额外需求。