Tsinghua University, Tsinghua University, Tsinghua University, Tsinghua University, Tsinghua University, Tsinghua University, Tsinghua University, Tsinghua University, South China Normal University, Tsinghua University, affiliation not provided to SSRN, Chinese Academy of Agricultural Sciences (CAAS), Tsinghua University, Tsinghua University, University of Oklahoma and affiliation not provided to SSRN