World City: A city that has influence on a global scale and serves not just a country or region but the whole world. They act as a major centre for finance, trade, business, politics, culture, science, publishing, and sporting events. The 3 main world cities are London, New York and Tokyo.
o Services concentrate in these world cities, propelled by the “informationalisation” of the economy. World cities grow because they are resource bases for knowledge that companies need access to, as they are located near universities, policymakers and R+D offices for other companies. This knowledge fuels innovation and entrepreneurship within the companies.
o Within these world cities people are able to meet and share tacit knowledge (learning through discussion and face to face contact) increasing the likelihood of innovative ideas being shared. Where two companies, groups or individuals achieve mutual benefits by working closely together, it is known as an economy with high levels of synergy.
o Most low-value activities such as manufacturing have moved to other cities or countries and instead there are many jobs at the top that require high levels of education. To support these jobs there are also a wide range of semi-casual, low paid jobs that have few career prospects, leading to a polarised labour force and an increasing spatial differentiation in the distribution in types of residential areas in the cites.
o Other important cities are often found in the same countries as world cities. The number of important cities is roughly proportional to the number of world cites in that region. These other important cites are within a suitable distance for face-to-face meetings by air and high speed rail travel.
Megacities: A metropolitan area with a total population in excess of 10 million. The density is normally above 2000 persons/km². It can be made up of 2 or more metropolitan areas that converge upon each other. Tokyo-Yokohama is the largest metropolitan area with a population of 34.4 million. Mumbai is the 5th largest with a population of 19.4 million.
Millionaire City: A city with over a million inhabitants. India and China have the most of these. By 2020, India is expected to have 68 millionaire cities. Birmingham is an example of a millionaire city.
Until the middle of the 20th century the biggest cities in the world were in the developed countries, such as New York and London. In the 1950s New York was recognised as a megacity. Since 1950, many cities in the developing world have become megacities, due to natural increase and high rates of rural-urban migration. In 1960, 9 of the top 19 biggest cities were in developing countries and by 2008, 48 of the 68 largest cities were in developing countries, the majority in Asia and in particular countries with emerging economies such as Delhi and Mumbai in India, and São Paulo in Brazil. However, none of the world’s largest cities are in Africa. There are currently 21 megacities. It is…