1. Song Xi Chen is Professor of Statistics, Department of Statistics, Iowa State University, Ames, IA 50010 and Department of Business Statistics and Econometrics, Guanghua School of Management, Peking University, China . Cheng Yong Tang is Assistant Professor, Department of Statistics and Applied Probability, National University of Singapore, Singapore 117546 . Vincent T. Mule, Jr. is from the U.S. Census Bureau, Washington, DC 20233 . We thank the U.S. Census Bureau for supporting our research. We are...