医疗服务提供者的执业领域之争与美国医疗保险计划（Medicare）的支付规则

Barriers to entry and scope of work restrictions are common features of US labor markets, especially within healthcare industries. However, concerns over access and costs of care have encouraged some deregulation. We empirically explore relaxed occupational rules of anesthesia care whereby physician-trained anesthesiologists and certified registered nurse anesthetists (CRNAs) perform overlapping services but often engage in joint production. After CRNAs were granted practice independence, we find only modest (3%) reductions in anesthesiologist billing for CRNA supervision and no evidence of greater use of CRNAs. Our results caution policymakers against overestimating the downstream impact resulting from removing these provider regulations.