1. Department of Agricultural Economics, University of Cordoba, Cordoba, Spain
2. Department of Economic Analysis, University of Zaragoza, Zaragoza, Spain
3. Water Security Research Group, International Institute for Applied Systems Analysis, Laxenburg, Austria
4. Department of Agricultural Economics, New Mexico State University, Las Cruces, NM, USA
5. Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain
6. School of Public Policy, University of California, Riverside, CA, USA