"During the past two decades, several public and private organizations have initiated programs to report publicly on the quality of medical care provided by specific hospitals and physicians. These programs have sparked broad debate among economists and policy makers concerning whether, and to what extent, they have improved or harmed medical productivity. We take advantage of a cross-sectional time series of different hospitals to address two fundamental questions about quality reporting. First, we examine whether report cards affect the distribution of patients across hospitals. Second, we determine whether report cards lead to improved medical quality among hospitals identified as particularly bad or good performers. Our data are from the longest-standing effort to measure and report health care quality the Cardiac Surgery Reporting System (CSRS) in New York State. Using data for 1991 through 1999, we find that CSRS affected both the volume of cases and future quality at hospitals identified as poor performers. Poor performing hospitals lost relatively healthy patients to competing facilities and experienced subsequent improvements in their performance as measured by risk-adjusted mortality"--National Bureau of Economic Research web site.