About the Authors

Shangfang Dai

Roles Data curation, Formal analysis, Investigation, Software, Validation, Writing – original draft

Affiliation School of Economics and Management, Tsinghua University, Beijing, China

Litao Han

Roles Conceptualization, Funding acquisition, Methodology, Supervision, Writing – review & editing

hanlitao@ruc.edu.cn

Affiliation School of Mathematics, Renmin University of China, Beijing, China

Competing Interests

The authors have declared that no competing interests exist.