Medicare's Prospective Payment System: The Victim of Aggregation Bias?
指出，基于医院层面成本函数估计的医保支付调整因子存在聚合偏差，因为不同医院的治疗成本函数不同，建议政策制定者采用患者层面的成本分析来设计预付费制度。
Since 1979, the Medicare program has relied upon hospital cost function parameter estimates to develop a hospital-level and, subsequently, patient-level reimbursement system. This paper demonstrates that the resulting payment adjusters are derived from biased estimates of the impact of patient and hospital-specific characteristics on individual treatment cost. Because hospitals appear to differ in their treatment cost functions, aggregation bias is present in such hospital cost models. Given this misspecification of the aggregate cost relationship, policymakers may be wise to consider patient-level cost analyses in their design of a patient-based prospective payment system. Copyright 1992 by MIT Press.