Dr. Casalino is Chief of the Division of Health Policy and Economics at Weill Cornell Medical College. He is interested in comparative effectiveness research focused on the healthcare delivery system. Put simply, this means asking: which types of organizations, using which types of processes, provide higher quality, cost-effective care? For example: at present, large numbers of primary care and specialist physician practices are being purchased by hospitals. Does this lead to higher or lower quality care? Higher or lower cost care? Dr. Casalino is particularly interested in unintended consequences of policies and in the effects of policies and of the organization of practice on physician professionalism and on racial/ethnic and socioeconomic disparities in healthcare delivery. At present, Dr. Casalino is working on projects that seek to define the demography of physician practices in the U.S., to describe the processes used by practices to improve care, and to analyze which factors are related to increased use of such processes. In addition, he has written a number of conceptual articles and reports intended to introduce new problems and/or to help provide new frameworks for thinking about problems. Dr. Casalino received his MD from the University of California, San Francisco, and his PhD in health services research from the University of California, Berkeley.