Jed Kolko: How Suburban Are Big American Cities?


Our analysis showed that the single best predictor of whether someone said his or her area was urban, suburban or rural was ZIP code density. Residents of ZIP codes with more than 2,213 households per square mile typically described their area as urban. Residents of neighborhoods with 102 to 2,213 households per square mile typically called their area suburban. In ZIP codes with fewer than 102 households per square mile, residents typically said they lived in a rural area.2 The density cutoff we found between urban and suburban — 2,213 households per square mile — is roughly equal to the density of ZIP codes 22046 (Falls Church in Northern Virginia); 91367 (Woodland Hills in California’s San Fernando Valley); and 07666 (Teaneck, New Jersey).

Other factors played minor roles in predicting how respondents described where they live. Residents of very small cities and towns rarely said they lived in an urban area, even if their neighborhood was quite dense. Residents of lower-income neighborhoods with older housing stock often said they lived in an urban area, even if it was lower-density. Residents of lower-density ZIP codes with lots of businesses sometimes called their neighborhoods urban; so did residents of lower-density, higher-income ZIP codes that are next to higher-density ZIP codes. But, in general, ZIP code density alone gets us most of the way to predicting whether people say they live in an urban, suburban or rural area.

Density makes a place vibrant. Density makes a city work. Density is the word and our answer to make better communities. Holly Whyte said "we are going to have to work with a much tighter pattern of spaces and development, and that our environment may be the better for it." 

We need to confront the need for density. I've denied and deluded myself that density was not the main issue. I've used words like 'compact', 'vibrant', and 'urban'. What is meant is more people per unit area, as well as mixed use and class. 

Higher density is better for a city. Again, Holly Whyte:

Density also has an important bearing on the look and feel of a neighborhood. If it is urban it ought to be urban. Most of our redevelopment projects are too loose in fabric. They would look better, as well as being more economical, if the scale were tighten up... concentration is the genius of the city, its reason for being. What it needs is not less people, but more, and if this means more density we have no need to feel guilty about it. The ultimate justification for building to higher densities is not that it is more efficient in land costs, but that is can make a better city.
— Holly Whyte - The Last Landscape