An Alternative Approach to the Calculation and Analysis of Connectivity in the World City Network

Empirical research on world cities often draws on Taylor's (2001) notion of an 'interlocking network model', in which office networks of globalized service firms are assumed to shape the spatialities of urban networks. In spite of its many merits, this approach is limited because the resultant adjacency matrices are not really fit for network-analytic calculations. We therefore propose a fresh analytical approach using a primary linkage algorithm that produces a one-mode directed graph based on Taylor's two-mode city/firm network data. The procedure has the advantage of creating less dense networks when compared to the interlocking network model, while nonetheless retaining the network structure apparent in the initial dataset. We randomize the empirical network with a bootstrapping simulation approach, and compare the simulated parameters of this null-model with our empirical network parameter (i.e. betweenness centrality). We find that our approach produces results that are comparable to those of the standard interlocking network model. However, because our approach is based on an actual graph representation and network analysis, we are able to assess cities' position in the network at large. For instance, we find that cities such as Tokyo, Sydney, Melbourne, Almaty and Karachi hold more strategic and valuable positions than suggested in the interlocking networks as they play a bridging role in connecting cities across regions. In general, we argue that our graph representation allows for further and deeper analysis of the original data, further extending world city network research into a theory-based empirical research approach.Comment: 18 pages, 9 figures, 2 table

Small worlds and board interlocking in Brazil: a longitudinal study of corporate networks, 1997-2007

Social Network Analysis (SNA) is an emerging research field in finance, above all in Brazil. This work is pioneering in that it is supported by reference to different areas of knowledge: social network analysis and corporate governance, for dealing with a similarly emerging topic in finance; interlocking boards, the purpose being to check the validity of the small-world model in the Brazilian capital market, and the existence of associations between the positioning of the firm in the network of corporate relationships and its worth. To do so official data relating to more than 400 companies listed in Brazil between 1997 and 2007 were used. The main results obtained suggest that the configuration of the networks of relationships between board members and companies reflects the small-world model. Furthermore, there seems to be a significant relationship between the firm’s centrality and its worth, described according to an “inverted U” curve, which suggests the existence of optimum values of social prominence in the corporate network.Board Interlocking; Social Network Analysis in Finance; Company Boards

Applied Bounded Model Checking for Interlocking System Designs

In this article the verification and validation of interlocking systems is investigated. Reviewing both geographical and route-related interlocking, the verification objectives can be structured from a perspective of computer science into (1) verification of static semantics, and (2) verification of behavioural (operational) semantics. The former checks that the plant model – that is, the software components reflecting the physical components of the interlocking system – has been set up in an adequate way. The latter investigates trains moving through the network, with the objective to uncover potential safety violations. From a formal methods perspective, these verification objectives can be approached by theorem proving, global, or bounded model checking. This article explains the techniques for application of bounded model checking techniques, and discusses their advantages in comparison to the alternative approaches

Probing the position of the Jakarta metropolitan area in global inter-urban networks through the lens of manufacturing firms

This paper presents an analysis of the position of the Jakarta metropolitan area (JMA) in global inter-urban networks. Our starting point is our aim to provide a more nuanced understanding of the JMA’s connectivity in world city networks (WCNs). To this end, we steer clear of top-down approaches, which tend to analyze cities in singular taxonomies of global prominence, and instead propose a framework that is attuned to the JMA’s contexts to provide an alternative and complementary reading of how the JMA has been inserted into the WCN. To this end, by drawing on the interlocking network model, which helps to proxy inter-urban networks based on the multi-locational operations of manufacturing firms, we examine the JMA’s network positionality on the global and national scales. The results provide evidence of the JMA’s global inter-city relations being strongly geared toward East Asian cities. In addition, the results suggest that the JMA cannot be detached from its national geography, as evidenced by its strong connections with cities located on the island of Java

A Research Odyssey: From interlocking network model to extraordinary cities

The paper charts a personal research journey that begins with the specification of the interlocking network model for cities and concludes with interpretation of cities as truly extraordinary. Three products of this model are discussed. First, this very specific model has generated a mini-literature on cities in globalisation and this is briefly outlined. Second, the model has been interpreted as a generic description of inter-city relations - central flow theory - and this is illustrated using historical examples. Third, there is a discussion of criticisms of the model and the relevance of green networks of extraordinary cities for thinking about the future of humanity

Light and circadian regulation of clock components aids flexible responses to environmental signals

The circadian clock measures time across a 24h period, increasing fitness by phasing biological processes to the most appropriate time of day. The interlocking feedback loop mechanism of the clock is conserved across species; however, the number of loops varies. Mathematical and computational analyses have suggested that loop complexity affects the overall flexibility of the oscillator, including its responses to entrainment signals. We used a discriminating experimental assay, at the transition between different photoperiods, in order to test this proposal in a minimal circadian network (in Ostreococcus tauri) and a more complex network (in Arabidopsis thaliana). Transcriptional and translational reporters in O.tauri primarily tracked dawn or dusk, whereas in A.thaliana, a wider range of responses were observed, consistent with its more flexible clock. Model analysis supported the requirement for this diversity of responses among the components of the more complex network. However, these and earlier data showed that the O.tauri network retains surprising flexibility, despite its simple circuit. We found that models constructed from experimental data can show flexibility either from multiple loops and/or from multiple light inputs. Our results suggest that O.tauri has adopted the latter strategy, possibly as a consequence of genomic reduction

Disentangling agglomeration and network externalities : a conceptual typology

Agglomeration and network externalities are fuzzy concepts. When different meanings are (un)intentionally juxtaposed in analyses of the agglomeration/network externalities-menagerie, researchers may reach inaccurate conclusions about how they interlock. Both externality types can be analytically combined, but only when one adopts a coherent approach to their conceptualization and operationalization, to which end we provide a combinatorial typology. We illustrate the typology by applying a state-of-the-art bipartite network projection detailing the presence of globalized producer services firms in cities in 2012. This leads to two one-mode graphs that can be validly interpreted as topological renderings of agglomeration and network externalities

Governance networks: Interlocking directorships of corporate and nonprofit boards

This study describes the interlocking networks of corporate directors serving on publicly listed corporate boards and those on the boards of nonprofit organizations in Western Australia in 2006. When this study was undertaken, the state was the beneficiary of a booming economy in resource development prior to the global financial crisis, yielding a substantial number of resource companies with their headquarters in Perth, the capital city of Western Australia. Through social network analysis using NetDraw, we trace the extent of interpersonal connections of prominent individuals who serve on these boards in this relatively isolated state in Australia. The network figures demonstrate the inner circle of companies and nonprofits with their interlocking directorships that suggest the growing interpenetration among the state, the market, and civil society. As a result of reduced government funding during the last two decades in Western Australia, nonprofit organizations have had to use market strategies to increase their revenues, which is one factor that has led to this greater interdependence between previously separate groups. Thus, market forces have blurred the boundaries that once separated private companies from nonprofit organizations, increasing the interlocking nature of their board directors

International sport federations in the world city network

In this article, we analyze the transnational urban geographies produced by international sport federations (ISFs) through their global, regional, and national headquarter locations. Data on the global urban presence of 35 major ISFs are examined through connectivity analysis and principal component analysis. The connectivity analysis reveals the relative dominance of cities in Europe and Pacific Asia, whereby Seoul, Tokyo, Kuala Lumpur, Cairo, and Lausanne stand out. The principal component analysis reveals the main subnetworks produced through ISF location decisions, which includes inter alia a "winter sports subnetwork" centered on Ankara, Belgrade, Helsinki, and Stockholm; an "Olympic subnetwork" centered on Lausanne; and a decentered subnetwork with truly "global sports."

Director Reputation, Ceo-Board Power, And The Dynamics Of Board Interlocks

This study advances research on CEO-board relationships, interlocking directorates, and director reputation by examining how contests for intraorganizational power can affect interorganizational ties. We propose that powerful top managers seek to maintain their control by selecting and retaining board members with experience on other, passive boards and excluding individuals with experience on more active boards. We also propose that powerful boards similarly seek to maintain their control by favoring directors with a reputation for more actively monitoring management and avoiding directors with experience on passive boards. Hypotheses are tested longitudinally using CEO-board data taken from 491 of the largest U.S. corporations over a recent seven-year period. The findings suggest that variation in CEO-board power relationships across organizations has contributed to a segmentation of the corporate director network. We discuss how our perspective can reconcile contrary views and debates on whether increased board control has diffused across large U.S. corporations.(.)Managemen