A global city (also called world city or sometimes alpha city or world center) is a city generally considered to be an important node in the global economic system. The concept comes from geography and urban studies and rests on the idea that globalization can be understood as largely created, facilitated and enacted in strategic geographic locales according to a hierarchy of importance to the operation of the global system of finance and trade.

The most complex of these entities is the "global city", whereby the linkages binding a city have a direct and tangible effect on global affairs through socio-economic means.^[1] The terminology of "global city", as opposed to megacity, was popularized by the sociologist Saskia Sassen in reference to her 1991 work, "The Global City: New York, London, Tokyo"^[2] though the term "world city" to describe cities which control a disproportionate amount of global business dates to at least May 1886, to a description of Liverpool by the Illustrated London News.^[3] Patrick Geddes also used the term "world city" later in 1915.^[4] Cities can fall from such categorization, as in the case of cities that have become less cosmopolitan and less internationally renowned in the current era, e.g., Kaliningrad, Russia; Thessaloniki, Greece; and Alexandria, Egypt.

Criteria[link]

Global City or world city status is seen as beneficial, and because of this many groups have tried to classify and rank which cities are seen as 'world cities' or 'non-world cities'.^[4] Although there is a consensus upon leading world cities,^[5] the criteria upon which a classification is made can affect which other cities are included.^[4] The criteria for identification tend either to be based on a "yardstick value" ("e.g., if the producer-service sector is the largest sector, then city X is a world city")^[4] or on an "imminent determination" ("if the producer-service sector of city X is greater than the producer-service sector of N other cities, then city X is a world city").^[4]

Economic characteristics[link]

The New York Stock Exchange

• Corporate headquarters for multinational corporations, international financial institutions, law firms, conglomerates, and stock exchanges that have influence over the world economy.
• Significant financial capacity/output: city/regional^[6] GDP^[7]
• Stock market indices^[8]/market capitalisation
• Financial service provision;^[9] e.g., banks, accountancy
• Costs of living^[10] personal wealth; e.g., number of billionaires^[11]

Political characteristics[link]

The Palace of Westminster

• Active influence on and participation in international events and world affairs; for example, Beijing, Berlin, Delhi, London, Moscow, Paris, Tokyo, and Washington are capitals of influential nations.
• Hosting headquarters for international organizations such as the World Bank, NATO, or the UN.
• A large proper, population of the municipality (the centre of a metropolitan area, typically several million) or agglomeration
• Diverse demographic constituencies^[12] based on various indicators:^[13] population, habitat,^[14] mobility,^[15] and urbanisation^[16]
• Quality of life standards^[17] or city development^[18]
• Expatriate communities

Cultural characteristics[link]

The Louvre in Paris

• International, first-name familiarity. Cities such as New York City, Los Angeles, Tokyo, Paris, and London are commonly referred to without needing to specify their country.
• Renowned cultural institutions (often with high endowments), such as notable museums and galleries, notable opera, major ballet companies, orchestras, notable film centres and theatre centres. A lively cultural scene, including film festivals (such as the Toronto International Film Festival), premieres, a thriving music scene, nightlife, an opera company, art galleries, street performers, and annual parades.^{[citation needed]}
• Several influential media outlets with an international reach, such as the BBC, Thompson Reuters, The New York Times, or Agence France-Presse.^{[citation needed]}
• A strong sporting community, including major sports facilities, home teams in major league sports, and the ability and historical experience to host international sporting events such as the Olympic Games, FIFA World Cup, or Grand Slam tennis events.^[19]
• Educational institutions; e.g., renown universities,^[20] international student attendance,^[21] research facilities
• Sites of pilgrimage for world religions (for example, Mecca, Jerusalem or Rome)
• Cities containing World Heritage Sites of historical and cultural significance^[22]
• Tourism throughout^{[citation needed]}
• City as site or subject in arts and media, television, film, video games, music, literature, magazines, articles, documentary^{[citation needed]}
• City as an often repeated historic reference, showcase, or symbolic actions^{[citation needed]}

Infrastructural characteristics[link]

Shinkansen

• An advanced transportation system that includes several highways and/or a large mass transit network offering multiple modes of transportation (rapid transit, light rail, regional rail, ferry, or bus), for example, the London Underground.
• Extensive and popular^[23] mass transit systems, prominent rail usage,^[24] road vehicle usage,^[25] major seaports^[26]
• A major international airport that serves as an established hub for several international airlines, for example, London Heathrow, Atlanta, Tokyo, and Chicago O'Hare. Airports with significant passenger traffic and international passengers traffic^[27] or cargo movements.
• An advanced communications infrastructure on which modern trans-national corporations rely, such as fiberoptics, Wi-Fi networks, cellular phone services, and other high-speed lines of communications. For example, Seoul and Tokyo are known as the digital and technology capitals of the world.^{[citation needed]}
• Health facilities; e.g., hospitals, medical laboratories
• Prominent skylines/skyscrapers (for example Chicago, Hong Kong, New York, Sao Paulo or Tokyo)^[28]
• Cities' telephone and mail services, airport flights-range, traffic congestion, availability of water, train facilities, nearby parks, hospitals, libraries, police stations, etc.

Studies[link]

GaWC studies[link]

The first attempt to define, categorize, and rank global cities using 'relational data' was made in 1998 by Jon Beaverstock, Richard G Smith and Peter J. Taylor, who all worked at that time at Loughborough University in the United Kingdom, and further by academic researchers like Ronald Daus in Germany (Free University of Berlin), who focused on «extra-European cities, predominantly in the Southern hemisphere».^[29] Together, Beaverstock, Smith and Taylor established the Globalization and World Cities Research Network. A roster of world cities was outlined in the GaWC Research Bulletin 5 and ranked cities based on their connectivity through four "advanced producer services": accountancy, advertising, banking/finance, and law.^[5] The GaWC inventory identifies three levels of global cities and several sub-ranks.

The 2004 rankings acknowledged 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" world city presence.

The 2010 roster of leading Alpha, Beta and Gamma world cities is as follows:^[30]

A map showing the distribution of GaWC-ranked world cities (2010 data).

Global Cities Index[link]

In 2008, the American journal Foreign Policy, in conjunction with consulting firm A.T. Kearney and the Chicago Council on Global Affairs, published a ranking of global cities, based on consultation with Saskia Sassen, Witold Rybczynski, and others. Foreign Policy noted that "the world’s biggest, most interconnected cities help set global agendas, weather transnational dangers, and serve as the hubs of global integration. They are the engines of growth for their countries and the gateways to the resources of their regions."^[31]

In 2012 the index was updated.^[32]

#1 New York

#2 London

#3 Paris

#4 Tokyo

#5 Hong Kong

#6 Los Angeles

#7 Chicago

#8 Seoul

#9 Brussels

#10 Washington, D.C.

Top ten global cities

Rank	Change	City	Rating
1		New York City	6.35
2		London	5.79
3	1	Paris	5.48
4	1	Tokyo	4.99
5		Hong Kong	4.56
6	1	Los Angeles	3.94
7	1	Chicago	3.66
8	2	Seoul	3.41
9	2	Brussels	3.33
10	3	Washington, D.C.	3.22
11	3	Singapore	3.20
12	3	Sydney	3.13
13	5	Vienna	3.11
14	1	Beijing	3.05
15	4	Boston	2.94
16	2	Toronto	2.92
17	5	San Francisco	2.89
18	1	Madrid	2.80
19	6	Moscow	2.77
20	4	Berlin	2.76
21		Shanghai	2.73
22		Buenos Aires	2.71
23	3	Frankfurt	2.69
24	2	Barcelona	2.59
25	1	Zurich	2.53

Rank	Change	City	Rating
26	3	Amsterdam	2.45
27	4	Stockholm	2.43
28		Rome	2.36
29	2	Dubai	2.32
30	1	Montreal	2.32
31	2	Munich	2.31
32	NA	Melbourne	2.25
33	2	São Paulo	2.19
34	4	Mexico City	2.18
35	3	Geneva	2.13
36	2	Miami	2.13
37	4	Istanbul	2.10
38		Houston	2.08
39	1	Atlanta	2.06
40	1	Taipei	2.05
41	1	Milan	2.01
42	5	Copenhagen	1.99
43	7	Bangkok	1.93
44		Dublin	1.82
45	1	Mumbai	1.79
46	4	Tel Aviv	1.69
47		Osaka	1.57
48	3	New Delhi	1.55
49	1	Kuala Lumpur	1.49
50	7	Cairo	1.49