[1] Tsinghua Univ, Sch Social Sci, Inst Econ, Beijing, Peoples R China
[2] Hunan Univ, Coll Business Adm, Changsha, Hunan, Peoples R China
[3] Fuzhou Univ, Sch Econ & Management, Fuzhou 350108, Fujian, Peoples R China
[4] Guangdong Univ Finance, Dept Appl Math, Guangzhou, Guangdong, Peoples R China