1. Lecturer, School of Economics and Management, Beijing Jiaotong Univ., Beijing 100044, PR China. ORCID: .
2. Professor, Dept. of Construction Management, College of Management and Economics, Tianjin Univ., Tianjin 300072, PR China. ORCID: .
3. Associate Professor, School of Urban Economics and Management, Beijing Univ. of Civil Engineering and Architecture, Beijing 100044, PR China. ORCID: .
4. Lecturer, School of Economics and Management, Hebei Univ. of Technology, Tianjin 300401, PR China (corresponding author). ORCID: .