In a commentary last week in Modern Healthcare, Bruce Vladeck, former head of the Health Care Financing Administration (now the Centers for Medicare & Medicaid Services), took aim at a recent study claiming to find a relationship between hospital market concentration and commercial prices. Noting that the study’s “data limitations and misspecified variables” made it impossible for the authors to draw accurate conclusions about a relationship between market structure and prices, he reaffirmed that any evidence for such a conclusion is “surprisingly thin.” He pointed to variables such as community demographics, the structure of private insurance markets and local medical culture as complicating factors that illustrate how resistant this issue is to the “simple solutions” suggested by the authors.