The question is not whether we want to live in cities. Obviously, a growing number of us do—otherwise we would not build so many of them. The real question is: In what kind of cities do we want to live? Compact or spread out? Old or new? Big or small?
Judging from the direction that American urbanism has taken during the second half of the 20th century, one answer is unequivocal—Americans want to live in cities that are spread out. Decentralization and dispersal, the results of a demand for private property, privacy, and detached family homes, have been facilitated by a succession of transportation and communication technologies: first, the railroad and the streetcar; later, the automobile and the airplane; lastly, the telephone, television, and the Internet. In addition, regional shopping malls, FedEx, UPS, the Home Shopping Network, and Amazon.com have helped people to spread out. Even environmental technologies—small sewage treatment facilities and micro power plants—have allowed people to live in more dispersed communities than in the past.
This is not simply suburbanization. All the cities that have experienced vigorous population growth during the second half of the 20th century—Houston; Phoenix, Ariz.; Dallas; San Jose, Calif.; Atlanta, Ga.—have grown by spreading out. These are horizontal cities, with generally low population densities, typically fewer than 10 people per acre compared with 15 to 20 people per acre in the older, vertical cities. Horizontal cities depend on automobiles for mass transportation and on trucks for the movement of goods. In a horizontal city, the difference between city and suburb is indistinct. People in both live chiefly in individual houses rather than in flats or apartment buildings, and the houses are organized in dispersed, semi-autonomous planned communities that are different from the urban neighborhoods of the past. Versions of the dispersed city can be found in large cities such as Los Angeles, small cities such as Las Vegas, and in the metropolitan areas surrounding all cities, old and new.
The Technological Reshaping of Metropolitan America, a 1995 report of the federal Office of Technology Assessment, concluded, "Given the technological and economic trends toward decentralization, America's central and inner cities are unlikely to regain their earlier dominance." Decentralization suits an economy that depends on flexibility, adaptability, and rapid change. Dispersal also suits an increasingly heterogeneous society, which is the exact opposite of what is implied by that misleading term global village. Despite living in an urban civilization, Americans are not more alike today, they are more dissimilar, and dispersal handily accommodates different lifestyles, values, and, of course, incomes.
Horizontal cities have another characteristic—they tend to be new. During the industrial era, advanced infrastructure, good ports, and large workforces gave established cities a head start. In a postindustrial era, however, being old is no longer an advantage; a new community needs but to lay down fiber-optic cables, build a walkable downtown, and entice a Whole Foods and a Target to be competitive. I am always struck, returning from Seattle or Denver, Colo., to my home in Philadelphia, by the urban contrasts. The difference is not just a century's worth of accumulated industrial grime compared with unsullied newness, or that so much of Philadelphia's infrastructure—the stone viaducts, the narrow turnpikes, the commuter railroad lines—are relics of the past. In Philadelphia, the new always seems slightly makeshift, shoehorned into an old mold that doesn't quite fit. The past is part of the city's charm—and what keeps me here—but it exacts a price in terms of efficiency, convenience, and endless maintenance. An old city is like an old car: It still runs, it will get you there, but it doesn't have the safety features, conveniences, and efficiencies of a newer model.
Newness has other advantages. New cities generally have new, and often streamlined, building regulations, new social compacts between management and labor, and new ways of doing things. Houston's absence of zoning, its less restrictive building regulations, and its lower construction costs, for example, mean that according to the 2006 census, the average owner-occupied dwelling cost $126,000, compared with $496,000 in New York City. Since incomes in greater Houston are only slightly lower than in New York, that makes the city much more affordable for the middle class and, according to Harvard economist Edward L. Glaeser, accounts for Houston's greater appeal. Between 2000 and 2007, the city grew by 19.4 percent, compared with just 2.7 percent for New York. The presence of a large middle-class workforce also explains why Houston has more blue-collar manufacturing jobs than New York.
Another answer to what kind of cities we want seems to be: "warmer." A 2008 national survey of the major metropolitan areas that appealed most to people found that the favorites—Denver, San Diego, Seattle, Orlando, and Tampa—all shared "warm weather, a casual lifestyle and rapid growth." In fact, all of the Top 10 cities on the list were in temperate climates, seven in the West and three in the South. It also helps if a city is close to attractive natural amenities such as lakes, mountains, beaches, or the desert. Given the popular interest in the outdoors, and outdoor activities, nearby wilderness areas have become important urban amenities. As David Brooks put it, "These [favorite cities] are places where you can imagine yourself with a stuffed garage—filled with skis, kayaks, soccer equipment, hiking boots and boating equipment. These are places you can imagine yourself leading an active outdoor lifestyle." Industrial cities didn't need beautiful settings; postindustrial cities do.