What is the impact on intra-national trade and regional economic outcomes when the quality and lane-capacity of an existing paved road network is expanded significantly? We investigate this question for the case of Turkey, which undertook a large-scale public investment in roads during the 2000s. Using spatially disaggregated data on road upgrades and domestic transactions, we estimate a large positive impact of reduced travel times on trade as well as local manufacturing employment and wages. A quantitative exercise using a workhorse model of spatial equilibrium implies heterogeneous effects across locations, with aggregate real income gains reaching 2–3% in the long-run. Reductions in travel times increased local employment-to-population ratio but had no effect on local population. We extend the model by endogenizing the labor supply decision to capture this finding. The model-implied elasticity of employment rates to travel time reductions captures about one-third of the empirical elasticity.

中文翻译：

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道路容量、国内贸易和区域成果

当现有铺面道路网络的质量和车道容量显着扩大时，对国内贸易和区域经济结果有何影响？我们以土耳其为例调查这个问题，该国在 2000 年代对道路进行了大规模的公共投资。使用道路升级和国内交易的空间分类数据，我们估计旅行时间减少对贸易以及当地制造业就业和工资的巨大积极影响。使用空间均衡主力模型进行的定量研究意味着不同地区的异质效应，从长远来看，总实际收入增长达到 2-3%。旅行时间的减少提高了当地就业人口的比例，但对当地人口没有影响。我们通过将劳动力供应决策内生化来扩展模型以捕捉这一发现。就业率对旅行时间减少的模型隐含弹性约占经验弹性的三分之一。