For more than two years, Nancy Krieger and her colleagues have worked with approximately 1 million records from databases of the Massachusetts and Rhode Island Departments of Public Health as well as U.S. census data. The basic aim of the project, said Krieger, is to come up with measures of socioeconomic position of residents using data from the census. The researchers then link the data to geographical locations that can be readily used by any health department to track ongoing trends. There is little information on how differences in socioeconomic position affect health, though the discussion about health disparities among Americans has never before been so prominent on the national agenda. The researchers are working to fill those gaps.