The Globalization and World Cities Research Network (GaWC) is a think tank that studies the relationships between world cities in the context of globalization. It is based in the geography department of Loughborough University in Leicestershire, United Kingdom. GaWC was founded by Peter J. Taylor in 1998. Together with Jon Beaverstock and Richard G. Smith, they create the GaWC's bi-annual categorization of world cities into "Alpha", "Beta" and "Gamma" tiers, based upon their international connectedness.
The GaWC examines cities worldwide to narrow them down to a roster of world cities, then ranks these based on their connectivity through four "advanced producer services": accountancy, advertising, banking/finance, and law. The GaWC inventory ranks city economics more heavily than political or cultural factors[why?]. Beyond the categories of "Alpha" world cities (with four sub-categories), "Beta" world cities (three sub-categories), and "Gamma" world cities (three sub-categories), the GaWC cities include additional cities at "High sufficiency" and "Sufficiency" level.
GaWC has published city classifications in 1998, 2000, 2004, 2008, 2010, 2012, 2016, 2018 and 2020. The 2004 rankings added several new indicators while continuing to rank city economics more heavily than political or cultural factors. The 2008 roster, similar to the 1998 version, is sorted into categories of Alpha world cities (with four sub-categories), Beta world cities (three sub-categories), Gamma world cities (three sub-categories), and additional cities with High sufficiency or Sufficiency presence.
The cities in the 2020 classification are as follows.
(1) or (1) indicates a city moved 1 category up or down since the 2018 classification.
Alpha level cities are linked to major economic states and regions and into the world economy and are classified into four sections, Alpha ++, Alpha +, Alpha, and Alpha - cities.
Alpha ++ cities are cities most integrated with the global economy:
Alpha + cities are highly integrated cities, filling advanced service needs:
Beta level cities are cities that link moderate economic regions to the world economy and are classified into three sections, Beta +, Beta, and Beta − cities.
Gamma level cities are cities that link smaller economic regions into the world economy and are classified into three sections, Gamma +, Gamma, and Gamma − cities.
Sufficiency level cities are cities that have a sufficient degree of services so as not to be overly dependent on world cities. This is sorted into High Sufficiency cities and Sufficiency cities.
The following cities were included in the 2018 edition, but not in the 2020 edition: