1. Cambridge Econometrics, Covent Garden, Cambridge CB1 2HT, UK
2. Global Systems Institute, Department of Geography, University of Exeter, Exeter EX4 4QE, UK
3. Faculty of Economics, Meijo University, Nagoya 468-0073, Japan
4. Graduate School of Economics, Kyoto University, Kyoto 606-8501, Japan
5. School of Environment and Natural Resources, Renmin University of China, Beijing 100872, China
6. Department of Food and Resource Economics, Korea University, Anam-dong, Seongbuk-gu, Seoul 02841, Republic of Korea