Centrality and power have become common foci for world city network research and frequently serve as tools for describing cities’ position or status in the system. However, these concepts are difficult to define and measure. Often they are treated as equivalent: more central cities have more power. This paper challenges this assumed equivalence by proposing conceptually distinct definitions and developing two new measures that allow them to be differentiated empirically. Applying the proposed measures in a hypothetical world city network and the Internet backbone network reveals that centrality and power are distinct and suggests that world cities should be viewed as arising from multidimensional network positions that define multiple types: quintessential world cities that are both central and powerful (such as New York and London), hub world cities that are central but not powerful (such as Washington and Brussels) and gateway world cities that are powerful but not central (such as Miami and Stockholm).

In a recent article, Zachary Neal (2011) distinguishes between centrality and power in world city networks and proposes two measures of recursive power and centrality. His effort to clarify oversimplistic interpretations of relational measures of power and position in world city networks is appreciated. However, Neal’s effort to innovate methodologically is based on theoretical reasoning that is dubious when applied to world city networks. And his attempt to develop new measures is flawed since he conflates ‘eigenvector centrality’ with ‘beta centrality’ and then argues that ‘eigenvector- based approaches’ to recursive power and centrality are ill-suited to world city networks. The main problem is that his measures of ‘recursive’ centrality and power are not recursive at all and thus are of very limited utility. It is concluded that established eigenvector centrality measures used in past research (which Neal critiques) provide more useful gauges of power and centrality in world city networks than his new indexes.

Powerful cities are often distinguished from others by the concentration and mix of resources at their disposal. The right mix, the right people and skills, along with the ability to do something with them marks off the more powerful from the less powerful cities. In that respect, far reaching influence and control are the hallmarks of a powerful city. Often implicit in this view, however, is an understanding of power as something which a city possesses, a capacity for domination and control embedded in the city itself which gives it a ranking above others. This paper sets out an alternative way of thinking about how power ‘works’ for cities that is not based upon hierarchical domination or a zero sum game. The first part outlines a view of power as a means to an end, a medium that enables cities to hold networks together and bridge connections. Following that, the ‘power to’ run the networks, to exercise power with rather than over others, is illustrated through the example of the international division of labour that holds between the London and Frankfurt financial centres. In particular, the key role of intermediate elites as brokers is highlighted. This analysis is developed further in the final section by taking the example of Sydney as a powerful ‘switching point’, but one where intermediaries broker and bridge global networks to gain advantage – not through practices of domination and control, but more subtle modes of power such as manipulation and inducement, which operate at the expense of others. In so doing, the ‘power to’ make things happen folds over into power over others.

The research constitutes the first effort to test the claim found in the world city theoretical literature that, as world cities strengthen ties with each other, their linkages with their countries’ hinterlands and national urban systems will weaken. This research offers a more nuanced exploration of this hypothesis by taking into account variation in the nature of the state across countries in which world cities are located as well as the source of global capital in the world cities. Specifically, the research reported here suggests that three types of world cities—market-centred bourgeois world cities (MWC), state-centred political bureaucratic world cities (SWC) and dual-role world cities (DWC)—entail different deterritorialisation outcomes. Three countries that have prototypical global cities—Japan (SWC), China (DWC) and the US (MWC) are compared, applying longitudinal network modelling to relational data on national city networks. From 1993 to 2007, more globally connected MWCs weakened their national ties. In contrast, higher global status has no significant effect on the integration of SWCs or DWCs with their national urban systems. This indicates that the type of state, but not the source of capital, conditions whether the world city will deterritorialise vis-a`-vis its national city system.

This article presents an analysis of the determinants of connectivity change in the world city network (WCN). Drawing on the theoretical research of Saskia Sassen and the subsequent empirical research of the Globalization and World Cities (GaWC) group, connectivity in the WCN is measured through the networked location strategies of globalised service firms. Based on a calculation of the total connectivity of 220 cities across the world for 2000 and 2004, a measurement of connectivity change is produced for this time-period. This measure of connectivity change is then used as the dependent variable in a linear regression model through which are tested a number of hypotheses concerning the determinants of connectivity change. The study analyses WCN change both in general and in sectoral terms, and also examines how the prior presence of service firms impacts connectivity change.

This is an empirical paper that measures and interprets changes in intercity relations at the global scale in the period 2000–08. It draws on the network model devised by the Globalization and World Cities (GaWC) research group to measure global connectivities for 132 cities across the world in 2000 and 2008. The measurements for both years are adjusted so that a coherent set of services/cities is used. A range of statistical techniques is used to explore these changes at the city level and the regional scale. The most notable changes are: the general rise of connectivity in the world city network; the loss of global connectivity of US and sub-Saharan African cities (Los Angeles, San Francisco and Miami in particular); and, the gain in global connectivity of south Asian, Chinese and eastern European cities (Shanghai, Beijing and Moscow in particular).

A number of researchers have recently tried to map the contours of a transnational urban network. Although these empirical studies have great merits in making a closer connection to theoretical ideas on a genuine urban network, they sometimes fail to recognise that the whole idea of cities as ‘nodes’ in a transnational urban network is a heuristic at best. To assess this underdeveloped analytical connection, a taxonomy of dominant empirical and theoretical approaches is constructed. Contrasting both taxonomies reveals a mismatch between theory and measurement. This mismatch is addressed in more detail through four separate but entwined examples of conceptual conflation: a lack of rigour in the employed terminologies; inappropriate discussions of results against the background of other concepts; the inadequate delineation of the urban area; and, the limited analytical value of infrastructure-based analyses.

Examining networks of cities in the world rather than ‘world cityness’, the study offers a ‘Southern’ perspective on world city research. It includes places not ordinarily considered. Fourteen years of sample data on cross-border, intercity airline traffic are used as time-series relational information. The data express links between two of South Africa’s principal cities and cities elsewhere in Africa and beyond. The analysis shows persistent and intensifying links, but also sporadic and unstable intercity relations. A gathering concentration on proximate city pairs is apparent. The research also reveals that urban areas commonly regarded as topping the world city hierarchy mix with smaller and less well-known African places in the rankings of connections with Johannesburg and Cape Town. The complex intercity links which constitute urban significance on the world map are not reducible to a subordinate nesting of Third World city ties in a dominant First World matrix.

Some interesting changes have been taking place in the urbanisation processes of Latin American countries in the past few decades, some of which are definitely related to global processes. The empirical evidence of this relation is hard to pin down due to the lack of data sources, but in this paper it is suggested that the growth in volume and diversity of mobility relations between cities can be indicators of an overlapping of urban phenomena and global processes. A diachronic analysis (1970–2008) of Latin American air transport connectivity is used to evaluate the growth and the degree of cohesion of the internal relational systems and changes and continuities in the external relational systems. Even though air transport is an indicator to be complemented with other indicators when analysing global relations, the results indicate a continuation of existing Latin American structures (centralism and polarisation) and the emergence of new forms of dependence (tourism and migration), which should not be overlooked in the study of global relational systems.

The term ‘global city’ bestows an image of an urban place that is contemporary, international, multicultural, ‘wired’, cosmopolitan, polarising and having geographically boundless power. Nevertheless, the literature fails to produce a common identity for setting the global city apart empirically and in analysing policy issues related to it. This paper argues and tests the proposition that the global city is better described and analysed from a holistic construct of competing perspectives. To do this, it identifies seven global city dimensions; subjects the dimensions to a principal components analysis; and, uses the resulting composite factor to drive a K-means cluster analysis to differentiate 53 US urbanised areas. The results identify significant clusters that set apart global cities and provide a broadened base for cross-disciplinary comparative urban research.

We contend that interaction networks are far superior to cultural area and regional approaches for bounding human social systems. This article discusses methodological and conceptual issues in bounding human social systems and their interactions with the natural environment and examines several recent innovations in information technology that facilitate the study of interaction networks.