Think about it. When were cities founded? Will new cities be created? By whom were the modern cities built? How did our current cities grow and why did they grow the way they did (and still do)?
Cities started to appear during the Neolithic ages, some disappeared, and new ones were built. The location of a city is important since infrastructure and natural resources need to be available. The latest cities seem to have appeared during the industrialization period when peasants were looking for jobs in factories, leading to massive growth.
During the ages, the layout of cities evolved in different ways. Early cities grew in a seemingly unplanned fashion with irregular road networks. Later cities, in for example the US, applied grid- and cul-de-sac layouts. New, planned cities, have been built in, for instance, India, Brazil and the United Arab Emirates.
In Sweden, there have been suggestions to create new cities instead of letting the existing ones grow. The Guardian wrote a DIY instruction, and there are many problems to take care of, both practical and political.
To build a new city, you have to find a good location with plenty of water and existing infrastructure not too far away. Then you have to get your hands on the land in some way and negotiate with existing municipalities. The governments of some countries have greater authority to take land into possession than in other nations. The Monarchs had much more power a couple of centuries ago.
Once the city is being built, you need to attract companies to make people want to live and work there. Starting from scratch gives you the advantage to avoid the mistakes done in earlier cities (and makes it possible to make new errors). You can plan infrastructure, where city zones should be located and how the city should evolve over time.
There has been a lot of buzz regarding so-called smart cities where information technology is integrated into the city to manage its assets. The motivation is reduced cost and reduced resource usage.
To attract companies to the city they need to be offered advantages compared to staying where they are right now. The city could, for example, negotiate free trade agreements with the government. Aqaba in Jordan has some tax exemptions meaning that you need to go through customs when leaving the city.
A privately held city could be operated as a company where individuals have to apply for “citizenship” effectively meaning that people become employed by the city. The economy of the city would probably look similar to plan economy with touches of capitalism.
The city would need to have its own security forces like police, firefighters and so on. If a country contains many single autonomous cities, a group of lucky people would have the benefits of being citizens, but others would have to be taken care of by the government in the zones not owned by the individual cities. Similar contemporary trends can be observed where private companies compete with public transportation taking over the profitable high volume routes ignoring the countryside unless forced to.
Companies with political influence and potential to establish new cities would be oil companies, technology giants like Google, Apple, Microsoft, and Amazon, multinational giants like Nestlé and Procter Gamble and so on. By establishing new cities, the companies could foster their citizens to become “fanboys” who loyally consume the products and services being offered by the companies. They would have to operate in countries where the government can accept the special privileges requested.
Is this a future we want? Maybe some variant of this is inevitable, especially if we start colonizing new planets where the land in between the cities is inhabitable. Perhaps gated communities are one step in the direction of privatization of cities.