路网密度与城市扩张程度对共同富裕水平的影响

王广鹏¹，来逢波²，聂成龙¹，梁梓浩¹

1.山东交通学院交通与物流工程学院，山东 济南  250357；2.潍坊学院，山东 潍坊  261061

摘要：为分析交通基础设施与城市空间扩展对共同富裕的影响，基于我国31个省、自治区、直辖市2011—2022年的面板数据，采用双向固定效应模型和中介效应模型，以共同富裕水平为被解释变量，以路网密度和城市扩张程度为核心解释变量，对外开放水平、政府干预程度、技术水平、互联网发展水平为控制变量，实证检验路网密度与城市扩张程度对共同富裕水平的影响及其区域异质性，并探究城市扩张程度的中介效应。结果表明：1）路网密度、城市扩张程度对共同富裕水平均有显著的正向促进作用。2）路网密度对共同富裕水平的影响存在显著的区域异质性，在东部和东北地区，路网密度的系数显著为负，路网密度对共同富裕水平产生抑制作用；在中部和西部地区，路网密度的系数显著为正，路网密度对共同富裕水平产生积极的正向影响。3）城市扩张程度在路网密度影响共同富裕水平的过程中发挥部分中介效应，中介效应占总效应的25%，路网密度不仅直接促进共同富裕水平，还通过推动城市扩张程度间接发挥作用。应科学规划路网布局以强化城乡要素流动，协同推进新型城镇化以释放城市扩张的辐射效应，并根据区域差异实施差异化交通基础设施策略，全方位释放路网密度与城市扩张程度对共同富裕水平的协同推动作用。

关键词：路网密度；城市扩张程度；共同富裕水平；双向固定效应模型；中介效应模型

Impacts of road network density and urban expansion extent on common prosperity level

WANG Guangpeng¹, LAI Fengbo², NIE Chenglong¹, LIANG Zihao¹

1.School of Transportation and Logistics Engineering, Shandong Jiaotong University, Jinan 250357, China；

2.Weifang University, Weifang 261061, China

Abstract: To analyze the influence of transportation infrastructure and urban spatial expansion on common prosperity, panel data for 31 provincial-level regions in China (provinces, autonomous regions, and municipalities) from 2011 to 2022 are used. Two-way fixed-effects and mediation models are employed, with the level of common prosperity as the dependent variable and road network density and the urban expansion extent as the key explanatory variables. The effects of road network density and urban expansion extent on common prosperity level and their regional heterogeneity are empirically examined, and the mediating role of urban expansion is investigated. The results indicate that both road network density and urban expansion extent exert significant positive impacts on common prosperity; there is pronounced regional heterogeneity in the effect of road network density, its coefficient is significantly negative in the eastern and northeastern regions (indicating an inhibitory effect), while significantly positive in the central and western regions (indicating a beneficial effect); urban expansion extent provides a partial mediating effect in the pathway through which road network density affects common prosperity level, accounting for 25% of the total effect, implying that road network density promotes common prosperity level both directly and indirectly via urban expansion. Policy recommendations include scientifically planning road network layouts to strengthen urban-rural factor flows, advancing new-type urbanization in a coordinated manner to unlock the spillover effects of urban expansion extent, and implementing differentiated transportation infrastructure strategies tailored to regional conditions, thereby fully leveraging the synergistic promotion of common prosperity by road network density and urban expansion.

Keywords: road network density; urban expansion extent; common prosperity; two-way fixed-effects model; mediation model