[1] Peking Univ, Inst Digital Finance, Natl Sch Dev, Beijing, Peoples R China
[2] Jiangxi Co Ltd, China Mobile Commun Grp, Fu Zhou Branch, Ganzhou, Peoples R China
[3] Chinese Acad Social Sci, Inst Quantitat & Technol Econ, Dongcheng, Peoples R China
[4] Chinese Acad Social Sci, CASS Lab Econ Big Data & Policy, Dongcheng, Peoples R China