1. School of Economics & Management, Northwest University, Xi’an, Shaanxi 710127, P. R. China
2. School of Economics and Finance, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, P. R. China
3. Department of Finance, Fintech & Blockchain Research Center and Big Data Research Center, Asia University, Wufeng, Taichung 41354, Taiwan
4. Department of Medical Research, China Medical University Hospital, Wufeng, Taichung 41354, Taiwan
5. Business, Economic and Public Policy Research Centre, Hong Kong Shue Yan University, Hong Kong
6. School of Mathematics and Physics, Wenzhou University, Wenzhou, Zhejiang 325035, P. R. China