1. Institute for Global Environmental Strategies, 2108-11, Kamiyamaguchi, Hayama, Kanagawa 240-0115, Japan
2. Graduate School of Economics, Hitotsubashi University, 2-1 Naka, Kunitachi, Tokyo 186-8601, Japan
3. Faculty of Economics, Khon Kaen University, 123 Mittraphap Road, Muang District, Khon Kaen, Thailand