1. Antai College of Economics and Management; Shanghai Jiao Tong University; Shanghai 200052 China
2. School of Business and Management; The Hong Kong University of Science and Technology; Hong Kong
3. School of Engineering; The Hong Kong University of Science and Technology; Hong Kong
4. Department of Industrial Engineering & Operations Research; University of California; Berkeley California 94720
5. Department of Civil and Environmental Engineering; University of California; Berkeley California 94720