The Change of the Structure of System of Cities by Providing Rapid Transportation Systems

我们使用一个简单的一般均衡模型与集聚经济，允许与现有的聚集相关的锁定效应的描述，研究人口位置的动态。通过假设政府应用稍微不同的决策规则（成本效益评估规则），并通过逐一改善线路，改善运输网络，特别是铁路网络，优先改善效益成本比最高的线路，这篇论文试图证明城市系统将以这样一种方式发展，即人口确实会聚集在一些占主导地位的地点，这取决于地理条件和网络改善的历史顺序。该模型突出了收益递增的主要来源之一，即，通过生产中的技术外部性产生的空间集聚。该模型旨在专门模拟应力如何 ...更多信息 城市系统的结构将随着铁路网络的改善而演变。在本研究中，我们专门关注后一种类型的外部性，以描述城市系统将如何演变，以应对由于铁路网络的改善而增加的面对面通信的可能性。成本效益评估规则保证政府做出局部最优决策，给定的网络演变的历史。局部最优改进的序列不需要达到全局最优状态。如果城市系统的内在特征是均衡的多重性，这一点尤其正确。虽然只有有限数量的模拟实验进行处理，我们已经成功地说明，简单的继承的成本效益评估规则可能会导致高度集中的系统效率低下。就我们的模拟实验而言，当决策是通过粗略和天真的成本效益计算做出时，这一点尤其明显。少

We examines the dynamics of population location using a simple general equilibrium model with agglomeration economies that permits a description of the lock-in effects associated with existing agglomerations. By assuming that the government applies slightly different decision rules (cost-benefit evaluation rules) and that it improves the transport network, especially the railway network, through one by one link improvements in the order that the links with the highest benefit-cost ratios are given the highest priority to be improved, this paper tries to demonstrate that city systems will evolve in such a manner that population will indeed cluster in some dominant locations, and that this depends both on the geographical conditions and historical order of network improvement.The model highlights one of the major sources of increasing returns, i.e., spatial agglomeration generated through technological externalities in production. The model is designed to exclusively simulate how the str … More ucture of city systems will evolve in response to railway network improvement. In this research, we exclusively focused upon the latter types of externality to describe how city systems will evolve in response to increasing possibilities of face-to-face communications due to railway network improvements.The cost-benefit evaluation rule guarantees the government to make the local optimal decisions, given the history of the network evolution. The successions of the local optimal improvement need not to reach the global optimal state. This is especially true if the city system is inherently characterized by the multiplicity of the equilibria. Though only limited number of simulation experiments are dealt with, we have succeeded to illustrate that the simple succession of the cost-benefit evaluation rules may end up with highly centralized systems having low efficiency. As far as our simulation experiments are concerned, this is especially clear when decisions are made by coarse and naive cost-benefit calculation. Less