Rural-Urban Net Population Migration Rate of China Based on the Modified Keyfitz Urbanization Model
利用Keyfitz模型及其扩展形式，通过估算城镇化率和农村人口自然增长率，计算了1978-2011年中国城乡净人口迁移率，发现经济与体制改革对迁移率的周期波动有显著影响。
The data of the rural-urban population migration is an important basic data to study the policy of population migration, the development of urbanization, the reform of social security system and other issues.In China, because of the the survey methodology and the statistical range adjustment, the maasures of the urban areas and the urban population and other indicators lack the necessary convergence, so that it is very difficult to obtain the comparable rural- urban population migration ratio data which acrossing a long period of time just rely on official statistics alone. This paper uses the Keyfitz model and its extended foum as the study point, and then calculates the rural-urban net population migration rates since China's reform and openning up through estimating the urbanization rate and the rural population natural growth rate. The results show that there was a net increase of population from rural to urban areas for most of the years between 1978-2011, the rural-urban net population migration rate showed significant fluctuation, which the economic and the system reform had a more significant impact on the cyclical fluctuation. From the overall evolution trend, the fluctuations of the rural- urban population net migration rate had a more significant smoothing trend which may be derived from the impact of the residence and cocial security system deepening reform in recent years.