1. Senior Research Survey Methodologist in the Program for Research in Survey Methodology, RTI International 701 13th St NW #750, Washington, DC 20005, USA
2. Distinguished Fellow, RTI International and Associate Director, The Odum Institute for Research in Social Science at the University of North Carolina at Chapel Hill, 3040 East Cornwallis Road, P.O. Box 12194, Research Triangle Park, NC27709-2194, USA
3. Team Leader, Office of Statistical Methods and Research, U.S. Energy Information Administration, 1000 Independence Ave. SW, Washington, DC 20585, USA