About the Authors

Yang Xu

Roles Formal analysis, Methodology, Software, Writing – original draft

junnie5@163.com

Affiliations Zhongtai Securities Institute for Financial Studies, Shandong University, Jinan, Shandong, China, Department of Statistics, Northwestern University, Evanston, Illinois, United States of America

Hongmei Jiang

Roles Formal analysis, Methodology, Supervision, Writing – review & editing

Affiliation Department of Statistics, Northwestern University, Evanston, Illinois, United States of America

Wenxin Jiang

Roles Formal analysis, Methodology, Supervision, Writing – review & editing

Affiliation Department of Statistics, Northwestern University, Evanston, Illinois, United States of America

Competing Interests

The authors have declared that no competing interests exist.