Abstract: Family income largely affects fertility behaviors under the universal twochild policy. The Fifth Plenary Session of the 19th CPC Central Committee proposed to reduce the cost of fertility, parenting and education. Using CFPS data collected before and after the recent family planning policy change, this research develops a twochild family income conversion sub matrix decomposition method, and empirically analyzes the characteristics of two-child family income mobility. A binomial logistic regression model is established to analyze the factors influencing the income mobility of twochild families. The results show that: (1)During the relaxation of fertility policy, the absolute income of two-child families has moved downward, and the speed of movement has increased. The possibility of income rank downward mobility has also increased.(2)The impact of having two children on income mobility differs across families in different income groups. Middleincome groups are the most affected while the highincome group is the least affected.(3)In addition to the individual and households' characteristics, the imbalance of economic development and urbanrural differences are still the important macro factors affecting the income mobility of two-child families in China.

Keywords: Fertility Policy, Two-Child Family, Income Mobility

摘要： 家庭收入是影响全面两孩政策实施效果的重要因素，党的十九届五中全会明确提出要降低生育、养育、教育成本。在生育政策变化的视角下，基于中国家庭追踪调查（CFPS）中的生育及收入微观数据，构建二孩家庭收入转换子矩阵分解方法，分析二孩家庭收入流动性变动特征，并运用二元Logistic回归模型分析二孩家庭收入流动方向的影响因素。研究发现：（1）在生育政策逐步调整的过程中，二孩家庭绝对收入向下流动且幅度不断加大，收入位次向下流动的可能性也大大增加；（2）生育二孩对不同收入分组家庭的影响差异较大，3个中间收入分组家庭受到的影响最强，高收入分组家庭受到的影响最弱；（3）除了家庭个体特征外，经济发展不平衡、城乡二元结构等仍是影响中国二孩家庭收入流动方向的重要宏观因素。

关键词: 生育政策, 二孩家庭, 收入流动