农民工举家迁移决策的理论分析及检验

A Theory Analysis on the Family Migration Decision of Rural-urban Migrants

近年来,农民工以家庭形式进入城市务工经商逐渐增加,经典的迁移理论对城乡劳动力流动现象给出了令人满意的解释,但是传统模型更多关注个体,而缺少对家庭进行整体性分析。本文以农民工举家迁移的决策机制为基础构建了一个多期动态模型,模型以生活成本为核心,分析了对城市生活成本信息的积累与修正,以及城市社会网络规模的变化对举家迁移的影响。模型表明农民工家庭中最初迁移者对城市信息的积累和家庭社会网络的扩大能够降低迁移成本不确定带来的风险,并促进举家迁移的发生。随后本文使用一项在北京市的农民工调查数据对上述模型进行了实证检验。是否举家迁移的Probit模型表明家庭结构、自经营的协同效应和务工的机会成本等影响迁移成本的重要变量都对流动人口举家迁移决策有关键性影响,验证了理论模型以迁移成本为核心假设的正当性。进一步的数据分析发现举家迁移的家庭进程务工时间较长,其城市的社会网络规模也普遍大于非举家迁移者。实证结果表明模型对农民工举家迁移的基本特征给出了较好的解释。

In recent years, rural-urban migration family are gradually increasing. The classic theories give a satisfactory explanation of rural urban migration phenomena. However, the traditional models almost focus on individual analysis rather than taking families as a integrity. This paper builds a multi-period dynamic model based on decision-making mechanisms of family migration, in which the cost of living play as a crucial role. The model analyzes the impact of urban living cost information accumulation and correction, as well as changes in the size of the urban social network of family migration. The model shows that by accumulation the information expansion of the social network in the city, it could be reduce the uncertainty of migration costs and promote family migration. A survey data of migrant workers in Beijing is used for the empirical analysis of the theory. Probit model indicates the family structure, synergies and opportunity cost that affect the cost of migration has a critical impact on family migration decisions. Further analysis shows, compared to those of non-family migration, the family migration processes of a longer migration history and a larger social network size in the city. All these empirical results show that the model could give a good explanation of family migration.