Britain invented the modern industrial city in the nineteenth century. But by the late 20th century most British cities had become basket cases. Today London overshadows the rest of the country, as the UK's only 'world city'. No other large country is anything like as economically and politically centralized. This concentration of power damages Britain's economy and fuels the sense of discontent felt by the millions of people for whom the capital seems like another planet. Yet it is cities that are fuelling economic growth around the world. Mike Emmerich looks at the DNA of cities and how it...