Harvard University's Michael Chernew will provide evidence and guidance to state and other policymakers to inform their efforts to control growth in health care spending. First, he will evaluate the impact of expanded service availability on health care spending in the commercial and Medicare population using IBM’s MarketScan Commercial Claims and Encounters Database, Medicare claims data, Medicare Provider of Service Files, and Medicare costs reports. Second, Chernew will examine trends in hospital administrative expenses using Medicare cost reports. Finally, he will develop policy recommendations for states seeking to leverage commissions to control health care spending. These recommendations will be crafted in collaboration with Harvard economist David Cutler, who serves on Massachusetts’s Health Policy Commission and is connected to a network of other states considering forming commissions. The guidance will focus on how state commissions should be structured, what authority they should have, and what data and analysis they should rely on.