Charles Vlek is professor emeritus of environmental psychology and decision research at the University of Groningen (NL). He is one of the founders of the European Research Conference on Subjective Probability, Utility and Decision Making (SPUDM). He co-organized the Dutch Societal Discussion on Energy Policy (1982/3) and participated in the Dutch Commission for Environmental Impacts Assessment (1986-'96). He has been ... Read morean editor of Acta Psychologica and is a consulting editor for the Journal of Environmental Psychology. Since 2003 he chairs a national research program on human society and environmental quality. Linda Steg is lecturer in environmental psychology at the University of Groningen. Her research focuses on measuring, understanding and changing environmentally significant behavior, like household energy use and car use. She is president elect of Division 4 'Environmental Psychology', and treasurer of Division 13 'Traffic and Transportation Psychology' of the International Association of Applied Psychology (IAAP). She coordinates the sustainability network of the International Association of People-Environment Studies (IAPS). Show Less