How can we compare New York, London, Paris, and Tokyo? defining spatial units of analysis

Paris-with 2.1 million inhabitants within its nineteenth-century walls and the peripheral freeway that surrounds its twenty arrondissements-was the prototypical "urban core" against which we selected comparable urban cores for New York, London, and Tokyo. The Paris population and area (105 square kilometers) are miniscule in comparison to Greater London's 7.3 million people and 1,590 square kilometers; New York City's 8 million people and 826 square kilometers; and Central Tokyo's 8.1 million people and 616 square kilometers. Rather, Paris is comparable to the urban core of these cities: for New York City, Manhattan with its 1.5 million population; for London, the fourteen boroughs known as Inner London with a population of 2.6 million. For Tokyo, with no conventional definition of an urban core, we relied on the criteria noted earlier and arrived at an urban core comprised of eleven inner wards (kus) that cover an area of sixty-seven square miles and had a 1995 population of two million. This area is roughly comparable to Paris, Manhattan, and Inner London in terms of population size and area. Except for Shitamachi, these inner wards are within the Yamanote loop line and include such important hub stations as Shinjuku, Shibuya, Ikebukuro (Toshima Ward), Shinagawa (Minato Ward), and Tokyo (Chiyoda Ward); Inner Tokyo, as defined here, is thus the area to which most commuters to Tokyo come to work. Since these eleven inner wards are all within about a five-mile radius of the Imperial Palace, they may clearly be said to be "central locations" within Central Tokyo.3 So defined, Inner Tokyo includes the major loci of political, economic, and social activities. Japan's legislative, executive, and judicial bodies are located in the three central wards, along with offices of the major political parties. Headquarters of Japan's major corporations are situated either in the three central business districts or in the new subcenters of Tokyo. Major parks, museums, and cultural facilities are also concentrated in the inner eleven wards. Finally, this definition of Inner Tokyo includes the city's past and present, as well as wards dominated by higher and lower occupational groups. In addition to the problem of choosing appropriate units of analysis, another important issue in any comparative inquiry involves structuring the comparisons around similarities as well as differences among the units being compared.