1. Center for International Development and Environmental Research (ZEU) Justus Liebig University Giessen Giessen Germany
2. Faculty of Economics and Business Studies, Department of Statistics and Econometrics Justus Liebig University Giessen Giessen Germany
3. Justus Liebig University Giessen Institute for Agricultural Policy and Market Research Giessen Germany
4. Institute for Landscape Ecology and Resources Management (ILR) Research Center for Bio Systems, Land Use and Nutrition (iFZ), Justus Liebig University Giessen Giessen Germany