乡城人口流动的理论解释: 农村人口退出视角
A Theory of Rural－Urban Migration: Revising the Todaro Model

摘要 中国乡城流动人口“流而不退”，传统的人口流动理论无法解释。文章在明晰农村人口退出内涵和必要性，分析农村人口退出与市民化、城市化等关系的基础上，从农村人口退出视角，加入制度因素对托达罗人口流动模型进行再修正。乡城流动人口的流动退出过程可分为两个阶段: 短期内，流动人口个体流动决策的依据是预期净收入最大化; 长期内，具有若干期流动经历的流动人口在进行家庭迁移退出决策时，决策依据应是包含制度净收益在内的家庭预期净收益最大化。模型分析结果显示农地制度是影响农村人口退出的核心因素，未来农村人口的顺利退出要求农村土地实现更多的功能，特别是财产功能; 深入推进农村土地制度，特别是退出制度需要进一步改革完善。
Abstract：The traditional migration theory has been unable to explain the phenomenon of“flowing without transferring”during the process of Chinese rural－urban population migration． Based on the Todaro modelwith the perspective of rural population transfer，this paper constructs a two－stage migration model by introducing institutional factors into the model，while clarifying the connotation and necessity of rural population transfer and analyzing the relationship between rural population transfer and citizenization and urbanization．In the short term，individual migration decision is made with the maximization of expected net income;in the long term，family migration decision is made with the maximization of expected net family income including the net institutional benefits． Our model suggests that rural land system is the core factor affecting rural population transfer． Successful transfer of the rural population requires that rural land be entitled more functions，especially the property function，and further reform of rural land system，especially the transfer system．