A live city is like a living organisms. A live city believes in proportionate growth of all its parts. If one part grows disproportionately, large or small, it faces problems. It knows that random and excessive growth of some parts is not good for its overall growth. A live city’s neural network needs are quite strong as its people need to connect with the mainstream. As the city grows its character changes; with growth the consumption pattern and behaviour of the populace also changes. A bigger city makes possible the economies of scale in infrastructure and facilitates and optimised delivery of social services. “An important result of urbanisation is the growth of occupations geared toward innovation and wealth creation,” say Geoffrey West and Luis Bettencourt. The character of the city changes when growth is driven by innovation and wealth creation. The continuous growth necessitates an “accelerating treadmill of dynamical cycles of innovation”.
Innovation is needed both for the organisms as well as cities, but their time scales are quite different. The innovation time scales of natural selection are very large. As the population increases and becomes more connected, the time scale of innovation in cities becomes shorter.
The pace of biological life slows down with increasing size of the organism. This is, however, not true for urban life. The pace of urban life in cities above a certain population increases as the size of the city increases. The growth of the cities as well as organisms is constrained by the availability of resources and their rates of consumption. A system collapses when it runs out of resources. To avoid this crisis it becomes necessary for the organism or the cities to bring major qualitative changes. In the case of cities, this includes innovation to ensure wealth and knowledge creation. “As we approach the collapse, a major innovation takes place and we start all over again”, West and Bettencourt explain.
To maintain liveability, the cities are required to innovate at a faster rate. Innovation and wealth creation have the possibility of growing faster at places where better opportunities are available. Big cities provide such opportunities. As the size of the city increases, along with it increases income, wealth, number of creative people, number of patentable discoveries, number of criminals, number of sicknesses, amount of waste, etc. West and Bettencourt argue that cities are mostly scaled-up, or scaled-down, versions of each other. Their model predicts that up to 85 percent of the character of a city is determined simply by its size. Only about 15 percent of a city’s character is distinctive. It means city administrators and the city’s aesthetics can play with only 15 per cent.
The major character of a city is due to “social networks” that consist of human clusters and the social interactions and hierarchies that flow from them. The research of West says that if a city doubles in size, it needs only 85 per cent more infrastructure. The flipside of massive city growth, West says, is that some of the negative factors such as crime and disease increase by 15 per cent above the doubling rate. In spite of this, West and Bettencourt think bigger can be better for cities. About big cities they say, “It may not be the feeling of many of us when we’re in them, but it is very good and no doubt that is the reason so many people are attracted to them.”