In their view, city residents “can experience their own urban location as if tourists, emphasizing aesthetic concerns.” Schools, churches, and neighborhood associations no longer form the city’s foundation. Instead, the city revolves around recreation, arts, culture, and restaurants—a system built for the newly liberated individual.

Demographic trends seem to bear out this vision. Over the past two decades, the percentage of families that have children has fallen in most of the country, but nowhere more dramatically than in our largest, densest urban areas. In cities with populations greater than 500,000, the population of children aged 14 and younger actually declined between 2000 and 2010, according to U.S. Census data, with New York, Chicago, Los Angeles, and Detroit experiencing the largest numerical drop. Many urban school districts—such as Chicago, which has 145,000 fewer school-age children than it had a decade ago—have seen enrollments plummet and are busily closing schools. The 14-and-younger population increased in only about one-third of all census-designated places, with the greatest rate of growth occurring in smaller urban areas with fewer than 250,000 residents.

Consider, too, the generation of Americans between the ages of 25 and 34 in 2000. By 2010, the core cities of the country’s 51 most populous metropolitan areas had lost, on average, 15 percent of that cohort, many of whom surely married and started having children during that period. While it’s not possible to determine where they went, note that suburbs saw an average 14 percent gain in that population during the same period.