A city acting as a focus for world finance and trade flows. Twenty-five cities effectively control almost all the world's financial transactions, and New York, London, and Tokyo are at the top of the hierarchy (N. Thrift and R. Martin 1994).

Global cities are also marked by large-scale in-migration and increasing income and occupational polarization. S. Sassen (1991) argues that global cities are witnessing large-scale immigration because migration to rich countries is partly set in motion by flows of foreign direct investment into poorer countries, and because ‘producer services’, like law, accountancy, management, and financial consulting, drive immigration through a demand for low-paid jobs. Global cities are the sites of increasing disparities in income and occupation because increased earnings inequality, together with sharply inflated prices for business inputs, commercial space, and labour, have led to informalization, often under ‘sweatshop’ conditions. Immigrants and other ethnic minorities cannot afford the luxury goods that are offered in global cities. They then seek necessary goods from ‘co-ethnic’ producers, and/or from other low-cost immigrant-run shops. Similarly, the type of niche-market small-batch goods aimed at more affluent consumers associated with the gentrification of large cities leads to labour-intensive, small-scale subcontracting, dominated by migrants.

The growth of the migrant population in global cities has led to an expansion of small-scale producers that can effectively compete with large chain stores and supermarkets, although competition is intense, returns are extremely marginal, and this in turn drives the demand for ever cheaper labour.

A Dictionary of Geography. Copyright © Susan Mayhew 1992, 1997, 2004. All rights reserved.