Beyond their long history as centers for international trade and banking, these cities now function as centers in four new ways: "first, as highly concentrated command points in the organization of the world economy; second, as key locations for finance and specialized service firms, which have replaced manufacturing as the leading economic sectors; third, as sites of production, including the production of innovations, in these leading industries; and fourth, as markets for the products and innovations produced." (p. 3) The thesis that Sassen has developed has been highly criticized ever since she released it, because she states that this is in every global city. The global cities that Sassen mostly deals with are the cities that play a large role in control and coordination of international capitalism. These are the cities that have separated themselves from national holds and constraints and have gone on to building their own power in distribution and production of goods. Major cities such as New York, London, and Tokyo lead the list. "These changes in the functioning of cities have had a massive impact upon both international economic activity and urban form. Cities concentrate control over vast resources, while finance and specialized service industries have restructured the urban social and economic order. Thus a new type of city has appeared. It is the global city."(Sassen 1991 pg 4) The reason this thesis is often questioned is because it links social and spatial relations in the city with the separation of labor. It doesn't seem to recognize that world cities (global cities) have always had major areas of poverty and wealth that is divided heavily by the poor and the rich.
Since the people in cities live in drastically different social and economic situations there are large differences in beliefs on the city and politics. Many people in cities seem to be involved in the economic prosperity of the city for the future.
