[1] Sichuan Agr Univ, Coll Econ, Chengdu 611130, Peoples R China
[2] King Saud Univ, Coll Food & Agr Sci, Dept Agr Econ, Riyadh 11451, Saudi Arabia
[3] Univ Waikato, Sch Accounting Finance & Econ SAFE, Hamilton, New Zealand
[4] Wuhan Univ, Sch Econ & Management, Wuhan 430072, Peoples R China
[5] Wuhan Univ, Ctr Ind Econ, Wuha 430072, Peoples R China
[6] Sindh Agr Univ, Fac Agr Social Sci, Dept Agr Econ, Tandojam, Pakistan