Simulations Towards the Dynamic Optimal Planning of Plural City-Systems

动态最优规划多元城市系统模拟模型是新城市经济学第三代模型的典型前沿之一，它具有以下特点：1)是一个可以进行大规模数值分析的模拟系统模型；2)不可延展性的资本积累过程是内生的、明确的；3)不是单一商品（行业）模式，而是多行业、多地区模式；4)从根本上论述了规模经济和集聚经济，这是所有大型城市的内在特征。如果可以解决线性规划软件的瓶颈（上限：数据密度为100的2000行x 6000列），我们的模型可以处理多城市和不同规模的城市。通过将该模型同时应用于全国不同规模的城市，将有可能开发出一个动态优化模型…更多区域发展和城市再增长的水平，沿着Kohno[alpha]*的图4至6所示的线。从图6中可以看出，大型城市的社会效益评价曲线是向下移动的，而农村城市的社会效益评价曲线是轻微向上移动的，如果有关公共当局对产业和人口采取顽固的分散化政策，收缩月城规模培育农村，则阴影区域的社会效益将无法实现。另一方面，我们可以看到，由于各种补贴政策，农村城市的规模可能会扩大到原本不会发展的地区，而阴影区域所显示的社会效益将以牺牲其他城市地区为代价而产生效率较低（机会成本）。这些都是诸如日本的国家综合发展计划等发展方案可能带来的后果。作为最新严谨的结果，请参考[1]。注（*）：[alpha]H， Kohno等人，“农村发展和城市再生的动态优化”，Peter Friedrich博士和Ian Masser教授（主编），区域分权的国际视角，Nomos Verlagsbesellschaft, Baden-Baden, 1987, pp. 254-277。少

Our model on the Simulathions Towards the Dynamic Optimal Planning Plural City-Systems can be described as one of the typical frontiers of the Third Generation Model in the New Urban Economics, in that it possesses the following characteristics :1) it is a simulation system model by which large-scale numerical analyses can be done ;2) the non-malleable capital accumulation process is set out endogenously and explicitly ;3) it is not a one commodity (industry) model, but a multi-industry and multi-region model ; and4) it treats fundamentally the scale and agglomeration economies which are the intrinsic qualities of all the mammoth cities.If the bottleneck of linear programming software can be solved (upper limit : 2, 000 rows x 6, 000 columns in the data density of one hundreds), our model can tackle multi-cities and different scaled ones. By applying the model to the various different scaled cities over the country concurrently, it will be possible to develop a dynamic optimization mod … More el of both regional development and urban re-growth, along the lines shown in the figures 4 to 6 in Kohno[alpha]*.In Figure 6, it can be seen that the social benefit evaluation curve of a mammoth city shifts downward, while that of a rural city moves slightly upward, and the social benefit in the shaded area will not be realized if the public authorities concerned adopt a obstinate decentralisation policy with respect to industry and population and contract the scale of momoth cities to foster rural regions. on the other hand, it will be seen that, owing to various subsidization policies, the scale of rural city may expand to areas which would not, otherwise, have been developed, and the social benefits shown by the shaded areas will be generated less efficiently at the expense of other urban regions (opportunity costs). These are the consequences that are likely to be brought by development programmes such as the National Comprehensive Development plan of Japan.As the latest and rigorous results, please refer to the reference[1].Note(*) : [alpha]H, Kohno et al., "Dynamic Optimisation of Rural Development and Urban Regrowth" in Prof. Dr. Peter Friedrich and Ian Masser (Eds), International Perspectives of Regional Decentralisation, Nomos Verlagsbesellschaft, Baden-Baden, 1987, pp. 254-277. Less