1. PBC School of Finance, Tsinghua University, 100083 Beijing, China;
2. Faculty of Business and Economics, University of Melbourne, Carlton, Victoria 3010, Australia;
3. Lerner College of Business and Economics, University of Delaware, Newark, Delaware 19716;
4. School of Management and Economics, Shenzhen Finance Institute, CUHK-Business School, The Chinese University of Hong Kong, Shenzhen, China;
5. PBC School of Finance, Tsinghua University, 100083 Beijing, China