In the last decades, many European hospital markets witnessed a wave of mergers leading to increased levels of market concentration. The effects of hospital mergers and the effectiveness of competition enforcement have been discussed by politicians but understudied by academics. This report...

We examine variation in US hospital quality across ownership, chain membership, and market concentration. We use a new measure of quality derived from the penalties imposed on hospitals under the flagship Hospital Readmissions Reduction Program. We document a robust and sizable negative...