1. Mike Baiocchi is Doctoral Student, Dylan S. Small is Associate Professor, and Paul R. Rosenbaum is Professor , Department of Statistics, Wharton School, University of Pennsylvania, Philadelphia, PA 19104-6340. Scott Lorch is Assistant Professor of Pediatrics at the University of Pennsylvania School of Medicine and an Attending Physician in the Division of Neonatology at The Children’s Hospital of Philadelphia. This work was supported by grant SES-0849370 from the Measurement, Methodology and Statistics...