World cities are those cities with global economic, national and cultural significance & authority. Because of this, they are major centres for communications, banking and finance, HQs of NGOs such as TNCs as well as tourist meccas.

The other major role of a world city is to provide a global cultural authority. Cultural authority is the associations between world cities and global culture. An example of a world city showing global sporting culture is the international TV/ Radio/ Internet coverage of soccer/rugby world cups, tennis/ golf opens as well as the Olympics via the globalisation of communications. Such cultural authority demands social infrastructure. This includes hotels, office blocks, airports, railways and entertainment, which allows people to make contact face to face & develop global social networks. Examples of such infrastructure include Wimbledon (London), Wembley (London) and Stadium Australia (Sydney).

Tourists then associate certain global culture between certain world cities. For example, Amsterdam is commonly associated with sex – this attracts many tourists p.a. to Amsterdam and generates much profit for economy of the Netherlands.

Such global economic and cultural roles of world cities have created strong global networks. That is, cities being connected to each other. This is done through:

1. Air transport- this is visible evidence of world city interaction. For example, from London to New York there are 240 flights per week and from Tokyo to Los Angeles there are 120 flights per week. New York has the need for three airports (JFK, La Guardia and Newark).
2. Sea transport- sea transport is commonly used to move bulky items from world city to world city as most world cities are on major sea routes. For example- in New York City, every 7 minutes, a ship will enter or leave port
3. Telecommunication circuits- the global phone network is dominated by world cities. Communications technology has brought places closer together (in terms of moving information and money) – time-space convergence has occurred. The most phone calls occur in London and New York each year (Manhattan (NY) has twice the telephones than an average nation).
4. Non-voice transfer systems- regular post, couriers, fax, email (especially – email has replaced traditional communication sources since the internet was introduced in the ‘90s as it has reduced time –a traditional barrier of information transfer). This has made communication on a global scale more affordable and more frequent. This is important as many companies operate in many nations- this results in many currencies used which is why rapid transfer of information is important.

Such methods above that have helped develop strong networks between world cities have also increased the relationships between world cities. As a result, there are three world cities that each dominate other world cities in the same region/time and economic zones. They are New York, Tokyo and London. Thus, there are 3 sectors:

• N American core: (NY) Chicago, Toronto, LA, Miami, etc.
• W European core: (London) Paris, Zurich, Milan, Amsterdam, etc.
• W Pacific core: (Tokyo) Sydney, Singapore, HK, Osaka, etc.

As one dominant world city closes activity, the focus switches to other world cities in different time zones – this has caused convergence to occur. (eg Tokyo to London to New York). This switching however makes it difficult for other cities to enter the high-end of world trade.

As can now be seen, the major roles of world cities are that of economic and cultural authority, and they operate within strong global networks. Such networks have strengthened relationships between world cities so that the world is constantly active, wherever you are positioned on the globe.