In How World Cities Change, Saskia Sassen argues that major cities may be losing population, but not because they’re drifting into irrelevance:
The shrinking of big-city populations has been both oversold and misinterpreted. Population is growing in some global cities, like Shanghai, London and Chicago. And in global cities where population is falling or stagnating, from New York to Manila, there is an inflow of highly educated 20- to 35-year-olds, along with an outflow of the very young and the old. What’s happening is a brutal triage: apartments that once held families now hold one single investment banker. And the space required by that single banker for offices, restaurants and shops can be two, three, four times more than that required by the family he or she replaces.