Scholars have written about cities since the birth of the city-state. In all disciplines—from philosophy to geography and political science—thinkers have explored the complex role of urban centers in human life. It is important to distinguish, however, between traditional examinations of the world’s metropolises and examinations of so-called global cities. This distinction lies fundamentally in the roles that cities play in the era of globalization, a period that most scholars trace back to the early 1990s and the end of the Cold War.
Before the age of globalization, many in the field of urban studies referred to major urban centers as “world cities,” a term coined by Patrick Geddes in his prescient 1915 book Cities in Evolution: An Introduction to the Town Planning Movement and to the Study of Civics. These rapidly growing world cities were defined as their nations’ economic, political, and cultural centers. By the mid-twentieth century, scholars began to signal the important role of these cities as nodes of power. Works such as Peter Hall’s The World Cities sounded an alarm for a “metropolitan explosion” that would surely accompany the significant influx of rural dwellers into urban areas. In the 1960s and 1970s, much of the literature on cities—and in the urban studies field in general—focused on crisis, decline, and the restructuring of cities associated with deindustrialization, post-Fordism, and the rise of transnational corporations that were reordering the world’s labor force. Salient works from that period include Jane Jacobs’s The Death and Life of Great American Cities and Scott Greer’s The Emerging City: Myth and Reality.
The era of globalization brought on a significant shift in the literature on cities: whereas earlier works analytically locate cities in the territorial container of the nation-state, more recent studies place them squarely in the global arena as actors in their own right. The relationships among cities and states is further discussed below, but the historical difference is worth emphasizing. Originally, cities were ranked in terms of their power and influence through the lens of the surrounding state. Writers such as Brian J. L. Berry (in a 1961 contribution to the journal Economic Development and Cultural Change), Allan Pred (in City-Systems in Advanced Economies: Past Growth, Present Processes, and Future Development Options), and Peter Hall (in The World Cities, mentioned above) viewed national territory as the scale on which to judge a city’s strength. Unlike more recent investigations, these earlier researchers gave far less weight to the significance of socioeconomic forces beyond national borders as consequential for urban development. As Neil Brenner and Roger Keil observe in the introduction to their edited collection The Global Cities Reader (discussed in detail later in this essay), “The cosmopolitan character of world cities was interpreted as an expression of their host states’ geopolitical power.”
This country-based focus changed with the emergence of works by critics of capitalism, who challenged the primacy of the nation-state in studies of urban political economy. Important examples are writers such as David Harvey (Social Justice and the City, The Limits to Capital, Consciousness and the Urban Experience, The Urbanization of Capital), Henri Lefebvre (Le droit à la ville and The Urban Revolution), and Manuel Castells (The Urban Question: A Marxist Approach). Their work in new urban sociology and economics explicitly linked the transformations and decline occurring in cities of the industrialized nations with the growth of a neoliberal, globalized economy. These works were accompanied by a wave of scholarship on globalization that began to focus on the increasing importance of cities in economic relations, as Peter Taylor reveals in his massive edited collection Global Cities: Critical Concepts in Urban Studies, discussed in detail in the next section of this essay. Works such as Cities in a Global Society, edited by Richard Knight and Gary Gappert, and Anthony King’s Global Cities: Post-Imperialism and the Internationalization of London highlight a new paradigm that placed cities squarely in the forefront of world economic activity.
A turning point in the study of global cities took place with the publication of two seminal works: John Friedmann’s article “The World City Hypothesis” (published in the journal Development and Change) and Saskia Sassen’s Cities in a World Economy. These marked a critical juncture in scholarship on the subject, explicitly establishing the role of major cities as interconnected nodes—the engines and loci of economic power in the global arena. In addition to Cities in a World Economy, Sassen’s contributions to the literature include The Global City: New York, London, Tokyo; The Mobility of Labour and Capital: A Study in International Investment and Labor Flow; and the edited volumes Global Networks, Linked Cities, and Deciphering the Global: Its Scales, Spaces and Subjects. To this day, Sassen remains a ubiquitous presence in writings on global cities, and her contributions appear in numerous collections discussed in this essay.
Though recent scholarship on the global city tends to focus on a new role for the metropolis in a globalized economy, some urbanists have for decades viewed and written about global cities as a long-standing historical phenomenon that must be analyzed as part of interconnected worldwide relations. Some examples of this school of thought are Janet Abu-Lughod’s New York, Chicago, Los Angeles: America’s Global Cities; Urbanization in the World-Economy, edited by Michael Timberlake; and numerous works by Christopher Chase-Dunn, most notably Global Formation: Structures of the World-Economy. These writers generally drew from Immanuel Wallerstein’s “world-systems theory” of the 1970s, which laid the foundation for a rejection of state-centered analyses in favor of a worldwide political economic perspective. They continue to play a significant role in analytical debates on global cities, and their view often complements that of globalization theorists.
 World-system theory is a sociological concept that envisions the interconnectedness of global labor markets by dividing the world into three categories: core (industrialized nations that benefit from the unequal economic power of the semi-periphery and the periphery); semi-periphery (generally middle-income nations that are supported by the periphery and supply labor to the core); and periphery (dependent developing nations that sustain the semi-periphery and core through labor and goods). See Immanuel Wallerstein’s four-volume The Modern World System (1974-2011).