1. R , Essen , Germany
2. WI–Leibniz Institute for Economic Research , Essen , Germany
3. Development Economics Group, Wageningen University and Research , Wageningen , the Netherlands
4. Wageningen Economic Research, Wageningen University and Research , Wageningen , the Netherlands
5. PBL–Netherlands Environmental Assessment Agency , the Netherlands
6. International Food Policy Research Institute , Lilongwe , Malawi