Dr. Fisher is the James W. Squires, MD Professor at Dartmouth Medical School and Director for Population Health and Policy at The Dartmouth Institute for Health Policy and Clinical Practice. He received his undergraduate and medical degrees from Harvard University and completed his internal medicine residency and public health training at the University of Washington. He is the director of the Dartmouth Atlas of Health Care and a member of the Institute of Medicine of the National Academy of Sciences.His research has focused on exploring the causes of the two-fold differences in spending observed across U.S. regions and health care systems, on understanding the consequences of these variations for health and health care, and on the development and testing of approaches to performance measurement and payment reform that can support improvement. The research revealed that most of the differences in spending are due not to differences in health status, preferences, prices or poverty, but rather to greater use of discretionary services, such as the use of the hospital as a site of care and specialist referrals or diagnostic tests that would not have been ordered in lower spending regions. The findings that per-capita spending -- on these services -- is essentially uncorrelated with either quality or health outcomes highlighted the potential opportunity to improve the efficiency of U.S. health care.His current policy work has focused on advancing the concept of "accountable care organizations" (ACOs) and includes co-directing, with Mark McClellan, a joint Brookings- Dartmouth program to advance ACOs through research, coordination of public and private initiatives and the creation of a learning collaborative that includes several pilot ACO sites across the U.S.