Regional Variation in Health Care Spending

We know from the Dartmouth Atlas that there are large regional variations in the cost of health care. Now it is being reported that academic medical centers are resisting attempts by the Institute of Medicine to study the sources of variation. The academic medical centers are raising the old argument that their patients are sicker and so cost more to treat (an argument that can easily be refuted). So, why would academic medical centers, the "guardians of the scientific basis of medical practice" resist a research study? Are they afraid of the answer?

Here's my hypothesis about why costs of care are different at different academic medical centers. The capital budgets for buildings and technology are different across the centers and positively correlated with costs. A center with a large capital budget must pay the debt on it's buildings and machines and it must utilize the buildings and technology fully to justify their costs and to justify better facilities and better technology in the future. It's just a hypotheses but it will be difficult to test since, unlike the public Canadian system, US hospitals do not make their budgets public.