交通基础设施、要素流动与城乡收入差距

大规模的基础设施建设,尤其是以铁路提速为代表的交通基础设施质量升级,是否会影响收入分配?通过将始于1997年的铁路提速事件视为交通基础设施质量提升的准自然实验,文章基于要素流动视角,运用双重差分方法实证检验了铁路提速对城乡收入分配的影响。机制分析表明,铁路提速通过促进劳动力、资本和技术等要素在城乡之间的流动,从而缩小城乡收入差距。实证分析表明,铁路提速显著缩小了城乡收入差距,缩小了大约5%-7%。铁路提速缩小城乡收入差距的作用主要来自于促进了人的流动、物的流动和技术流动,从而证实了要素流动机制。从城乡收入分配的角度而言,铁路提速显著有利于农村居民收入增加,从而缩小了城乡收入差距。动态效应表明,铁路提速初期缩小了城乡收入差距,但缩小作用递减;在2003年之后,铁路提速扩大了城乡收入差距。在这一过程中,2003年之前城乡收入差距缩小主要在于农村居民收入增长快于城市居民,从而城乡收入差距缩小;2003年之后,城市居民收入增幅大于农村居民,城乡收入差距开始扩大。这一动态效应的背后主要是由要素流动机制所致。基于多种稳健性检验,文章结论依然十分稳健。文章结论为提升交通基础设施质量、打破地区分割促进要素流动、提升农村地区要素集聚能力等政策提供了直接证据。

Transportation Infrastructure,Factors Mobility and Urban-rural Income Gap

Will large-scale infrastructure construction, especially railway upgrading represented by railway speed-up, affect income distribution? Based on the factor mobility perspective, this paper empirically examines the impact of Railway Speed-up on urban and rural income distribution by using the difference-in-differences method, which regards the railway speed-up incident that began in 1997 as a quasi-natural experiment to improve the quality of transport infrastructure. The mechanism analysis shows that the increase of railway speed can narrow the income gap between urban and rural areas by promoting the mobility of labor, capital and technology between urban and rural areas. Empirical analysis shows that the increase of railway speed significantly narrows the income gap between urban and rural areas, which is about 5% to 7%. Railway speed-up reduces the income gap between urban and rural areas mainly from promoting the mobility of labor, capita and technology, thus confirming the mechanism of factor mobility From the point of view of income distribution between urban and rural areas, the increase of railway speed is significantly beneficial to the increase of rural residents' income, thus narrowing the income gap between urban and rural areas. The dynamic effect shows that the income gap between urban and rural areas has been narrowed in the initial stage of railway speed-up, but the effect has been decreasing. After 2003, the income gap between urban and rural areas has been widened by railway speed-up. In this process, before 2003, the income gap between urban and rural residents narrowed mainly because the income growth of rural residents was faster than that of urban residents, thus narrowing the income gap between urban and rural residents. After 2003, the income growth rate of urban residents was larger than that of rural residents, and the income gap between urban and rural residents began to expand. This dynamic effect is mainly caused by the factor flow mechanism. We also make diversified robustness check. Sensitivity test shows that the income distribution effect of railway speed-up does not change with the change of sample interval. By setting up a new control group, it also shows that the effect of Railway Speed-up on urban-rural income gap is robust. Based on the framework of counterfactual test, it shows that the narrowing of income gap between urban and rural areas is not caused by other factors, but by the increase of railway speed. The robustness of the conclusion is further proved by matching method. Based on a variety of robustness tests, the conclusion of this paper is still very robust. The conclusions of this paper provide direct evidence for improving the quality of transport infrastructure, breaking regional segmentation, promoting factor flow, and enhancing the ability of factor agglomeration in rural areas.