1. School of Agricultural Economics and Rural Development, Renmin University of China, Beijing 100872, China
2. School of Sociology and Population Studies, Renmin University of China, Beijing 100872, China
3. School of Public Administration and Humanities, Dalian Maritime University, Dalian 116026, China
4. School of Public Administration, Hebei University of Economics and Business, Shijiazhuang 050061, China