For cities around the globe, 2020 was a seismic year, given the various impacts of COVID-19. Whilst some commentators called time of death on the city, others claimed that what we were experiencing was an acceleration of ongoing trends. What was agreed was that cities of the future would be very different in function and composition from those in the early part of the 21st century. But just how different was left very open. Yet the future of cities is unlikely to be one of universal abandonment: cities are the engines of economic growth across the globe, their power and influence increasing in inverse proportion to the decline in significance of the nation states that host them.

In an era characterised by global movements of people, money, goods and services, it is cities rather than countries that have become the primary focus for growth. As a consequence there has been a rush to become a world or global city, to be in the elite club of city-states. Some world cities such as London, Paris, Hong Kong, New York and San Francisco have enjoyed significant economic success in recent years, pulling ahead of the pack, attracting investment, people and attention, and using their clout and influence to good effect. Many other cities have lagged behind. These are our forgotten cities, our cities on the edge. In some of these places there is serious and persistent deprivation and poverty for those out of work and for those in precarious and low-paid employment, places such as Glasgow, Liverpool and Manchester in the UK, and Detroit, Pittsburgh and Baltimore in the US. In the UK's 2019 Index of Multiple Deprivation, Liverpool, Middlesbrough, Kingston upon Hull and Manchester topped the list of places characterised by deprivation, positions that have remained largely unchanged since 2015.3 Not only are these cities suffering from multiple deprivation – low incomes, poor skills and education, high crime, low employment – they seem unable to break out and improve, falling further behind the leading pack as they surge ahead.

Yet to present a picture in black and white, of flourishing global cities on the one hand, and relative and absolute declining cities on the other, would be an over-simplification.