Visionary Oxford professor Ian Goldin and The Economist's Tom Lee-Devlin show why the city is where the battles of inequality, social division, pandemics and climate change must be faced.

From centres of antiquity like Athens or Rome to modern metropolises like New York or Shanghai, cities throughout history have been the engines of human progress and the epicentres of our greatest achievements. Now, for the first time, more than half of humanity lives in cities, a share that continues to ris...