[1] Yunnan Univ, Sch Econ, Kunming, Yunnan, Peoples R China
[2] Jiangxi Univ Finance & Econ, Sch Finance, Nanchang, Jiangxi, Peoples R China
[3] Res Ctr Financial Management & Risk Prevent, Nanchang, Jiangxi, Peoples R China
[4] Hunan Agr Univ, Sch Econ, Changsha, Peoples R China