A half-century ago, many urbanists, including the late Lewis Mumford, believed that the inexorable shift to the suburbs was transforming cities into discarded parcels of "a disordered and disintegrating urban mass." Yet today, cities seem in many ways not to be disintegrating; rather, they are widely believed to be enjoying a revival of considerable proportions.

Such an assessment may be replacing the excessive pessimism of the 1960s with an overblown optimism. In reality, thoughout the last 40 years the suburbs have gained ground on the urban centers on almost every significant measure, from corporate headquarters to jobs in manufacturing, high technology, and business services.

So what about the ballyhooed urban revival?

What we are seeing is more like a subtle shift in the role of cities: from the commanding centers of global civilization to (at least in the advanced countries) a more peripheral function.

In many ways, this follows the prediction made a century ago by H.G. Wells, who said that cities would evolve from the unquestioned center of economic life into a "bazaar, a great gallery of shops and places of concourse and rendezvous."

Today, such cultural industries are becoming the focus of many urban political and business leaders. Instead of working to retain middle-class families, factory jobs, and economic superiority to the periphery, many cities now stress such ephemeral concepts as fashionability and "hipness" -- trend and style -- as the keys to their survival.

Montreal, for example, once a financial- and business-services center, seems intent on wiping out much of its remaining industrial base -- even its vibrant garment sector -- in favor of marketing the city as "hip and happening."

In many other cities -- including San Francisco, Miami, Boston, and New York -- culture-based tourism has emerged among the largest and most promising industries. And such fast-growing urban areas as Las Vegas and Orlando depend on providing "experiences," complete with eye-catching architecture and round-the-clock entertainment, as their base economy.

It is conceivable that New York, Boston or Chicago could poke along the 21st Century on the strength of their cultural attributes. They will probably never recover their former importance, but the yuppies, the aging affluent, and the temporary 20-somethings may have a good enough time not to notice.

The trend gets absurd, however, when it comes to smaller, less culturally endowed places. Take Detroit, the now desolate auto capital, whose political and business leaders hoped that by making it a "cool city" -- attracting gays, Bohemians, and young "creatives" -- they could find the answer to their profound economic and social problems. Unfortunately, though, many of those most attracted to culture, restaurants, and nose-ring parlors are not going to choose the Motor City over, well, about 50 alternatives.

This applies even to better-off smaller cities, such as Providence. Athough they have nicely restored central districts, attractive to professionals and college students, so do 100 or so other places. Some people might stay a year or two, maybe even a decade, but it's unlikely that culture will keep them after they've spent a weekend in Boston, not to mention New York.

A stratagem based on purported or real cultural attractions also fails to address some disturbing realities. Brookings Institution demographer Bill Frey says that many of the young people who are lured to "cool" urban places leave when they start businesses and families. He adds, "There are simply not enough yuppies to go around" for such cities.

If people stay in Providence, particularly people in their 30s, it is probably not for the art museums and cafes, but, rather, for more such mundane reasons as a low crime rate, affordable housing, family-friendly environments, and, more than anything else, jobs that pay decently.

This is where Providence and its environs can and often do outperform a New York or a Boston. Such advantages to being smaller, particularly when a city is well run, can spark a regional revival. A smaller community can often hone its development efforts, engage its citizens, and solve fundamental problems more easily than a big metropolis.

Yet city officials, planners, arts foundations and developers often don't adopt such an approach, because it can be difficult and expensive. It is much easier and more media-friendly (not to mention immediately profitable for developers and their political patrons) to plan some lovely or kicky project or endow a museum or sports facility with taxpayers' money than it is to nurture small businesses.

Meanwhile, it can be tough to persuade a factory not to move to Mexico or China; to rebuild failing schools; and to improve mass transit. Yet these economic fundamentals should remain the focus of progressive city officials and business and civic leaders.

As long as the leaders indulge their fantasies about being "hip" and neglect a firmer foundation, their cities will become little more than theme parks for the affluent -- and symbols of lost opportunity for everyone else.