论文标题
城市在一个减少运输成本的世界中
Cities in a world of diminishing transport costs
论文作者
论文摘要
经济活动有利于相互地理位置，并在空间上集中精力以形成城市。然而，在运输成本降低的世界中，物理接近的优势正在逐渐消失，城市在经济中的作用可能正在下降。为了洞悉城市的长期演变，我们分析了日本在1970 - 2015年期间的人口普查数据。我们发现，在国家规模上蓬勃发展，越来越大的城市表明，最终以单一的大型经济为中心。同时，每个较大的城市都以当地规模扁平化，这表明城市最终灭绝。我们将这种多尺度现象解释为通过自组织形成模式形成的实例，该实例在数学和生物学中得到了广泛研究。但是，城市的动态与数学或生物学机制不同，因为它们受位置之间的运输成本介导的经济相互作用的支配。我们的结果要求综合数学，生物学和经济学知识，以为适用于社会经济现象的一般模式形成理论打开大门。
Economic activities favor mutual geographical proximity and concentrate spatially to form cities. In a world of diminishing transport costs, however, the advantage of physical proximity is fading, and the role of cities in the economy may be declining. To provide insights into the long-run evolution of cities, we analyzed Japan's census data over the 1970--2015 period. We found that fewer and larger cities thrived at the national scale, suggesting an eventual mono-centric economy with a single megacity; simultaneously, each larger city flattened out at the local scale, suggesting an eventual extinction of cities. We interpret this multi-scale phenomenon as an instance of pattern formation by self-organization, which is widely studied in mathematics and biology. However, cities' dynamics are distinct from mathematical or biological mechanisms because they are governed by economic interactions mediated by transport costs between locations. Our results call for the synthesis of knowledge in mathematics, biology, and economics to open the door for a general pattern formation theory that is applicable to socioeconomic phenomena.
