1. Department of Management Science and e-Commerce, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
2. Department of Supply Chain Management, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
3. Department of Industrial Engineering and Operations Research & Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA
4. JD.com, Beijing, People's Republic of China