1. Department of Economics, University of Gothenburg, Gothenburg, Sweden.
2. Department of Mathematical Sciences, Chalmers University of Technology/University of Gothenburg, Gothenburg, Sweden.
3. Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
4. Division of Environmental Systems Analysis, Department of Technology Management and Economics, Chalmers University of Technology, Gothenburg, Sweden.