Calculation method of variables.

As China continues to implement its progressive fertility promotion policy, there has been a drastic decline in the fertility rate. Given that the migrant population constitutes more than a quarter of China’s total population, enhancing the willingness of this demographic to have additional children through policy-guided urban public services is pivotal for optimizing China’s population development strategy. This study analyzes the influence of urban public services on the reproductive intentions of the migrant population, utilizing data from 110,667 migrant families with one child, drawn from China’s Migrant Population Dynamic Monitoring data in 2016 and 2018. The data analysis reveals several key findings: (1) Urban public services, overall, exhibit a notable positive effect on the willingness of the migrant population to have more children, albeit with limitations and a declining trend. (2) Among urban public services, primary basic education significantly impacts the willingness of the migrant population to expand their families. (3) Large cities have created a ’reverse screening’ effect on the migrant population, leading to differential access to public services. This scenario caters effectively to the high human capital migrant individuals while reducing accessibility to livelihood public services for the low human capital migrant population. This paper critically evaluates China’s progressively adjusted fertility policy from the perspective of the migrant population. It underscores the necessity of establishing a comprehensive fertility support policy system across China.随着中国持续推进渐进式生育支持政策，我国生育率已出现大幅下滑。鉴于流动人口 (migrant population) 占全国总人口的四分之一以上，通过政策引导的城市公共服务提升该群体的再生育意愿，对于优化我国人口发展战略至关重要。本研究依托2016年与2018年中国流动人口动态监测调查数据中110667户已有一孩的流动人口家庭样本，剖析了城市公共服务对流动人口生育意愿的影响。数据分析揭示了多项核心结论：其一，城市公共服务整体对流动人口的再生育意愿具有显著正向影响，但该效应存在边界且呈弱化趋势；其二，在各类城市公共服务中，初等基础教育对流动人口扩大家庭生育规模的意愿影响最为显著；其三，大城市对流动人口形成了“反向筛选”效应，导致公共服务获取呈现差异化特征：该效应有效适配了高人力资本流动人口的需求，却降低了低人力资本流动人口获取民生类公共服务的可及性。本研究从流动人口视角出发，对我国渐进调整的生育政策展开批判性评估，并强调在全国范围内构建完备的生育支持政策体系的必要性。