It is frequently cited that more than half of us now live in cities. But it might come as more of a surprise to learn that the largest 300 cities, from New York to Guangzhou, account for nearly half (48%) of world economic output ... yet contain only 19% of world population.
Some cities are so powerful economically that they dwarf the rest of their country. The number of jobs they house and GDP they generate can account for almost half of their nations' output, if not more. They are no longer just cities: they are approaching the status of city-state.
London, for example, produces more than 30% of Britain's entire GDP. Neither is it the most extreme example: it is just 30th on our list of cities that most dominate their countries (see below).
The ranking is led by the "classic" city-states – Luxembourg, Macau, Hong Kong, Singapore, places where the city essentially is the country. But look at Brussels (59% of national GDP), Copenhagen (55%) or Tel Aviv (54%). Is it time we start calling them city-states, too?