There are three purposes: (1) to illustrate diversity amongst world cities; (2) to show how this reflects/constitutes power relativities between cities; and (3) to place debates on diversity and power on a firm empirical basis. The power of cities is interpreted both as a capacity ("power over") and as a medium ("power to"). World cities are treated as global service centres and the world city network is conceptualised as being "interlocked" through provision of business and financial services by global firms. The study is primarily empirical and uses a global data set comprising information on100 global service firms in 123 world cities. Seven different ways of measuring and illustrating power differentials are presented: global network connectivity, banking/finance connectivity, dominant centres, global command centres, regional command centres, high connectivity gateways, and gateways to emerging markets. These categories have been identified before but never specified as comprehensively and rigorously as here. Whereas power as command power is concentrated in the USA, western Europe and Tokyo, network power is much more geographically diffused transcending the old "North-South divide". Finally the focus on diversity makes problematic the lazy policy tendency for emulation of a few well-known "global cities". (C) 2002 Elsevier Science Ltd. All rights reserved.
