Most desirable cities lack children

A recent article in the New York Times claims that some of the most desirable cities to live in lack children. This is a problem for these cities because in terms of school systems stuggling to stay running, and loss of revanue. According to the article every child lost from a city can mean $5,000 taken away from the school systems.

So why don't these cities have children? The author suggests that the very things that make them desirable make them impracticle for children. Dense housing, fashionable restaurants, and mass transit. Many people who have moved out of the cities cite cost of living and desire for more space as reasons to leave.

But I ask is it really those factors that result in less kids, or is it less kids that results in those factors? Is it possible that these cities maintain such low crime rates and other desirable features because kids are not present to make things different. Is it possible that people actually move to these areas because of the lack of children. Do they stay untill they are ready to have kids then move to a more inviting area? Do the people of these upscale neighborhoods really want to wake up to the sound of skateboarders on the sidewalk outside their condos?