centrality and marginality

a new geography of centrality and marginality has emerged globally with financial centres concentrated in certain core cities with a large, increasingly disfranchised low-end work force helping provide services and backup. These services, financial, legal, operational are subject to a high degree of centralisation global cities (typically located in downtowns), managed by an expatriate elite runs a global network of service sub contractors and processing firms.
-- Sasskia Sassen (2001)