Feng Wang1,2, Yong Cai3, Ke Shen2, Stuart Gietel-Basten4. 1. Department of Sociology, University of California, Irvine, CA, USA. 2. School of Social Development and Public Policy, Fudan University, Shanghai, China. 3. Department of Sociology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. caiyong@unc.edu. 4. Division of Social Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.