Institution: | 1. School of Economics, Huazhong University of Science and Technology, Hubei 430074, P. R. China;School of Mathematics and Quantitative Economics, Dongbei University of Finance and Economics,Liaoning 116025, P. R. China 2. Key Laboratory for Applied Statistics of MOE and School of Mathematics and Statistics, Northeast Normal University, Jilin 130024, P. R. China |