[1] Univ Swat, Dept Econ, Khyber Pakhtunkhwa, Pakistan
[2] Univ Sharjah, Dept Finance & Econ, Sharjah, U Arab Emirates
[3] Abdullah Gul Univ, Dept Econ, Kayseri, Turkey
[4] Univ Int Business & Econ, Sch Int Trade & Econ, Beijing, Peoples R China
[5] Tsinghua Univ, Sch Econ & Management SEM, Beijing, Peoples R China