Aaron Pallas is the Arthur I. Gates Professor of Sociology and Education in the Department of Education Policy and Social Analysis at Teachers College, Columbia University. He also served as a statistician at the National Center for Education Statistics in the U.S. Department of Education, and taught at Michigan State University, Northwestern University, and Johns Hopkins University. Pallas has devoted the bulk of his career to the study of how schools sort students, especially the relationship between school organization and sorting processes and the linkages among schooling, learning, and the human life course. He is a Fellow of the American Educational Research Association and an elected member of the National Academy of Education and the Sociological Research Association. His most recent projects are explicitly designed to inform policymakers and other stakeholders about conditions in New York City public schools.