Tom Crompton is Change Strategist at WWF-UK, Godalming, Surrey, UK, where he has developed WWFs Strategies for Change Project. He is author of the WWFUK report Weathercocks and Signposts: The Environment Movement at a Crossroads and coauthor of Simple and Painless? The Limitations of Spillover in Environmental Campaigning. He holds a PhD in evolutionary biology from the University of Leicester, and a BA in natural sciences from the University of Cambridge, UK. Tim Kasser is Professor of Psychology at Knox College, in Galesburg, Illinois, USA, where he teaches classes on personality, clinical and abnormal psychology, and alternatives to consumerism. He has published dozens of scientific articles and book chapters on how peoples values and goals relate to their quality of life and their social and environmental behaviour. Kasser is also the author of The High Price of Materialism (MIT Press, 2002) and co-editor of Psychology and Consumer Culture (APA, 2004). He holds a PhD in psychology from the University of Rochester, New york, and a BA in psychology from Vanderbilt University, Tennessee.