Book excerpt: 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 expresses itself in their institutions, governance, public services, religion and culture. He argues that the UK needs a devolutionary ratchet, allowing major cities the freedom to seek devolution of any area of public spending that is not inherently national in nature (such as defence). Cities should have powers to raise some of their own taxes including business, property and sales based taxes and to increase them. He calls for sustained investment in transport and infrastructure, and also training. An innovation-centric industrial policy would also have an emphasis on the social fabric of cities and - crucially - their institutions.