The word city usually refers to a concentrated residential area with relatively high degree of urbanization. But countries vary from each other in terms of the concrete definition of city and the definition of its scope. Some take population size as the definition standard; while others take the historical, legal or administrative concept as the defining standard of city. In this Report city refers to the concentrated residential area under the governance of an administrative management center, including not only the urbanized area, but its linked ring of suburbs and villages. From this definition, it can be seen clearly that the city we refer to is a city in the administrative sense. Nevertheless, it is still necessary to explain the difference and connection between this concept of city and urbanized area and urban area specially.
City and region
The administrative division varies from country to country. Some countries set up the administrative unit of region below state (province) and above city, such asChinaandIndiaand many European countries. The administrative center of these regions is usually a dominating city; while the supreme administrative organ of the city governs some other cities. Under this circumstance, city only refers to the district itself, excluding other cities under it.
City and urbanized area.
The difference between city and urbanized area is that city is a region in the administrative sense; while urbanized area refers to a region in the social and economic sense, so that urbanized area means an urbanized region excluding the surrounding villages. According to this difference, urbanized areas are usually differentiated from the urban area. When an area is highly urbanized, the size of the urbanized area may be larger than certain urban area, because the former probably includes some areas of other cities. When the degree of urbanization of an area is relatively low, the size of the urbanized area will be smaller than the urban area, because the latter will include the suburb or village.
City and metropolitan area.
Some countries also have the concept of metropolitan area (e. g. theUSandCanada). This concept is in the statistical sense, namely, when the urbanization of some countries reaches certain degree, the connection of neighboring urban areas will be enhanced in terms of economy and society and the sharing degree of infrastructures will be high. In order to reflect the development of this area more comprehensively, statistics agencies will utilize these urban areas as a unit in statistics, namely, the metropolitan area. Therefore, generally speaking, the size of a metropolitan area is usually larger than that of the urban area.
What needs to be pointed out is that in the course of research, due to the accessibility of data, some cities adopt the concept of urbanized area, while others adopt the concept of metropolitan area. We have provided special explanations in these cases. Cities without special explanation are the cities in the administrative sense.
—— From“Global Urban Competitiveness Report（2007-2008）”，Pengfei Ni with Peter Karl Kresl