In her pioneering book The Global City, Saskia Sassen argued that certain cities in the post-industrial world have become central nodes in the new service economy, strategic sites for the acceleration of capital and information flows as well as spaces of increasing socio-economic polarization. One effect has been that such cities have gained in importance and power relative to nation-states. In this new collection of essays, Sassen and a distinguished group of contributors expand on the author's earlier work in a number of important ways, focusing on two key issues. First, they look at how information flows have bound global cities together in networks, creating a global city web whose constituent cities become "global" through the networks they participate in. Second, they investigate emerging global cities in the developing world - Sao Paulo, Shanghai, Hong Kong, Mexico City, Beirut, the Dubai - Iran corridor, and Buenos Aires. They show how these globalizing zones are not only replicating many features of the top tier of global cities, but are also generating new socio-economic patterns as well.