1. School of Public Administration and Policy, Renmin University of China , 323# Qiushi Building, No. 59, Zhongguancun Street, Haidian, Beijing 100872, China
2. Walter H. Shorenstein Asia-Pacific Research Center, Stanford University and NBER , Encina Hall E311, Stanford, CA 94305-6055, United States
3. Institute for Global Health and Development; National School of Development, Peking University , Langrun Garden, Beijing 100871, China