Vu Duy Nguyen Department of Tax and Custom, Academy of Finance, Hanoi, Vietnam   8 Phan Huy Chu Hoan Kiem Hanoi, Hanoi 844 VIetnam   vuduynguyenhvtc@gmail.com   https://www.hvtc.edu.vn/           JEL Areas: C5 : Econometric Modeling: General A2 : Economics Education and Teaching of Economics: General