Carl-Erik Särndal, Ph.D., is Consultant to National Statistical Agencies and was formerly Professor, Université de Montréal. He is the author, or a co-author, of many articles on survey sampling theory and applications.

Sixten Lundström, Ph.D., is Senior Methodological Adviser, Department of Population and Welfare Statistics, Statistics Sweden. He has extensive experience of survey practice, especially in the production of official statistics.