System Affiliation is the #1 Price Predictor
22% of regional price variation explained by health-system membership
Which system a hospital belongs to explains 22% of price variation across the region, more than any other measurable factor. Ownership type explains 4%; teaching status and bed size each explain less than 1%. The remaining 72% is contract-specific: the deals each hospital strikes with each insurer. The chart below shows why: hospitals cluster tightly around their system's price level.
Method: Variance decomposition across scored hospitals (system, ownership, teaching status, bed count as factors). Strip plot: systems with 3+ scored general hospitals; each dot is one hospital's price vs the regional median.
Verification: Cross-validated statistic
Data: recomputed on data refresh. Source: each hospital's CMS-mandated machine-readable file (45 CFR 180).