Paulo A.L.D. Nunes, Global Manager and Coordinator, Ecosystems Economics Unit, United Nations Environment Programme, Kenya, Jeroen C.J.M. van den Bergh, ICREA Professor, Autonomous University of Barcelona, Spain and Professor of Environmental and Resource Economics, Free University, Amsterdam, The Netherlands and Peter Nijkamp, Professor Emeritus, Vrije Universiteit Amsterdam, the Netherlands, the Centre for European Studies, Universitatea Alexandru Ioan Cuza din Iasi, Romania and the School of Public Policy and Management, Tsinghua University, China