[1] Beijing Inst Technol, Sch Management & Econ, 5 South Zhongguancun St, Beijing 100081, Peoples R China
[2] Wageningen Univ, Dev Econ Grp, Hollandseweg 1, NL-6706 KN Wageningen, Netherlands
[3] Northwest Agr & Forestry Univ, Coll Econ & Management, Yangling 712100, Shaanxi, Peoples R China
[4] Wageningen Univ, Ctr Crop Syst Anal, POB 430, NL-6700 AK Wageningen, Netherlands