交通设施与文化网络的贸易效应研究：基于产业与区域协调发展的视角

China's macro economy is facing the problem of "unbalanced and inadequate development" and infrastructure construction is an important means to promote the balanced development of regions and industries. Currently, related researches are compromised by four shortcomings, including the lack of study of domestic trade, negligence of spatial network character of infrastructures and their heterogeneous influences, as well as the lack of the impact of cultural network and the causal-effect identification of micro-mechanism. This project is aiming to complement above aspects by asking four questions: firstly, does the trade effect brought by transport infrastructure have the heterogeneity between central area and peripheral area or between competitive industry and inferior industry? secondly, does common culture promote market integration? thirdly, is there interaction effect between transportation infrastructure and cultural network on their impact on trade? Thirdly, is there any interaction between the trade effect of transport infrastructure and the trade effect of cultural network? fourthly, aiming at the heterogeneous trade effect resulting from transport infrastructure and cultural network, how should the government formulate effective policies for the balanced development of industries and regions? To answer these questions, this project will conduct four sub-topics : firstly, we will employ the new economic geography (NEG) model to expand the theoretical analysis of trade effects of infrastructure; secondly, we will use spatial data and geographic information system (GIS) to evaluate the network character of transportation and cultural indices, and further use buffer-zone analysis to match the location of firms with infrastructures; thirdly, we will employ instrumental variable (IV) regression to identify the causal effect relationship between inter-regional transportation and trade as well as the cultural, regional, and sectoral heterogeneity; finally, we will apply difference-in-difference (DID) combining IV methods to estimate the micro-mechanism with addressing endogeneity issues.

我国宏观经济面临发展“不平衡、不充分”的问题，发展交通设施是促进地区与产业协调发展的重要手段。当前相关研究存在若干问题：缺乏对国内贸易的研究，忽视对交通设施与文化的空间网络特征、异质性效应及其微观机制的因果识别。本研究的目的是补充上述不足，并回答以下问题：第一，交通设施的贸易效应是否在中心与边缘地区、优势及劣势产业之间存在异质性？第二，文化相似性能否促进市场整合？第三，交通设施与文化网络的贸易效应是否存在互动？第四，针对交通设施与文化网络产生的异质性贸易效应，政府如何制定有效的产业与区域协调发展政策？为此，我们从四方面展开研究：第一，利用新经济地理模型拓展交通设施贸易效应的理论研究；第二，利用GIS对空间微观数据测算交通设施与文化指标，并与企业进行空间匹配；第三，利用准实验方法识别市县间交通与贸易的因果关系，兼顾文化、产业与地区异质性；第四，利用准实验方法考察交通与文化贸易效应的微观机制。

交通与文化障碍是影响企业间贸易的两类交易成本，而交通改善与文化差异的缩小有助于降低此类成本，从而促进地区间和企业间贸易。当前的相关研究中缺乏对国内贸易的研究，而且忽视对交通设施与文化的空间网络特征、异质性效应及其微观机制的因果识别。为解决上述研究不足，本研究力图利用空间微观企业数据和准实验分析工具，对我国交通设施、文化网络与企业贸易之间的因果关系进行深入考察，从而为制定区域及产业协调发展政策提供理论与实证依据，也为现有研究做有益补充。. 本研究首先根据Chaney（2008）和Melitz & Redding（2015）构建理论分析框架，并利用福建省企业增值税发票数据构建了微观贸易数据库，分析了高速公路连通对企业销售的影响，发现交通改善显著促进了异地贸易而降低了本地贸易，由此促进了更大区域范围的市场整合。而且这种促进不仅表现在集约边际上，也体现在扩展边际上。同时，交通改善促使企业在距离更远的地区中搜寻贸易伙伴，并提高了销售企业的平均生产率水平。在进行替代样本估计、替代性交通方式分析、工具变量估计以及安慰剂检验后，发现基准结果是稳健的。研究还发现，企业高速入口距离存在显著的距离衰减效应，且对制造业行业的影响大于其他行业。而且，交通改善显著促进了不同地区产业链上下游企业之间的贸易，对于产业链的形成以及产业内部的分工深化具有明显的推动作用。. 其次，本研究还基于福建省企业微观贸易数据，利用固定效应面板模型研究了以交通改善（高速公路与高铁建设）、文化相近性（方言、姓氏）表示的贸易成本变化对企业间贸易的影响，并着重分析以方言代表的沟通成本、姓氏代表的信任成本、高速公路代表的运输成本以及高速铁路代表的信息成本之间的关系。交通改善并未促进其与相同姓氏企业通过高速公路进行的总贸易，但对相同方言企业间的高速公路总贸易则有显著的正向影响。以方言为代表的沟通成本与运输成本之间存在互补关系，而以姓氏代表的信任成本与运输成本之间的关系则不显著。