1. School of Economics and Business Administration, Chongqing Univ., No. 174 Shazhengjie, Shapingba, Chongqing 400044, China.
2. Doctoral Candidate, School of Economics and Business Administration, Chongqing Univ., No. 174 Shazhengjie, Shapingba, Chongqing 400044, China (corresponding author).