Abstract: Under the background of negative population growth, whether the scale of China's floating population will continue to grow and how its structure will change in the future are related to the construction goals of relevant social systems. Based on the data of the fifth, sixth, and seventh national population censuses, age structure standardization and decomposition methods are used to analyze the relative role of structure effect, scale effect, and intensity effect in the change of China's floating population in the past 20 years, and population projections are used to examine the future trend of the floating population. Research has found that the increase in the size of China's floating population in the past 20 years is mainly due to scale and intensity effects. Among them, the increase in the size of the urban floating population is mainly due to scale effects, while the increase in the rural floating population is mainly due to intensity effects; The structure effect has always had a negative impact, with the negative effect in the last 10 years being greater than that in the first 10 years. This negative structure effect shows similar behavior among different types of floating populations. Assuming the age-specific migration rate remains unchanged, the size of China's floating population will continue to decline in the future, and its age and urban-rural structure will undergo significant changes. The structure effect can be regarded as an intrinsic factor of natural growth, and the study of China's floating population must be situated within the context of negative population growth and population ageing.

Keywords: Population Negative Growth, Scale and structure of Floating Population, Structure Effect, Scale Effect, Intensity Effect

摘要： 在人口负增长背景下，未来中国流动人口规模是否仍会持续增长、结构如何变化等问题关涉甚广。基于第五次、第六次和第七次全国人口普查数据，运用年龄结构标准化和差异分解等方法，讨论结构、规模和强度3种效应在近20年中国流动人口规模和结构变化中的相对作用，并基于人口预测考察未来流动人口的发展趋势。研究发现，近20年，中国流动人口规模的增加主要源于规模效应和强度效应，其中，城镇主要源于规模效应，农村主要源于强度效应；结构效应一直呈负向作用，后10年的负向作用大于前10年，且在不同类型流动人口中表现基本相同；假设年龄别流动率不变，未来中国流动人口规模将持续下降，内部结构也将发生较大变化。结构效应可被视为内在自然增长因素，中国流动人口研究需被置于人口负增长的大背景下。

关键词: 人口负增长, 流动人口规模与结构, 结构效应, 规模效应, 强度效应