When city officials contact urban expert Joel Kotkin for guidance on how to attract people to their locales, they often ask about things that make him cringe. Instead of improving schools or infrastructure, they want to construct performing arts centers and pump up cultural offerings to lure the artsy and the hip.

That's not the way to revitalize cities, argues Mr. Kotkin, author of "The City: A Global History." To him, attracting and keeping people in urban environments is less about projecting an image of "cool" and more about providing the basics that encourage and support a strong middle class: jobs, schools, churches.

Kotkin's skepticism about relying on cultural enticements - which is not shared by all urbanists - is informed in part by his latest work, which looks back at the evolution of cities.

"No urban civilization has flourished long without middle-class families," he says in a recent interview in New York. The key to keeping people interested in city living is the idea of upward mobility. "That aspiration is very critical to urban life, it's important to the social order that people feel they can go somewhere."

By looking at the history of the city, from its origins in the Middle East to today's metropolises, he's observed that as cities evolved, their health typically rested on three factors: "the sacredness of place, the ability to provide security and project power, and ... the animating role of commerce," he writes. He argues that to be successful, today's cities must still be places that are "sacred, safe, and busy."

Without the idea of sacred space, for example, it's unlikely cities anywhere could have existed, Kotkin suggests. Religious leaders not only set the calendars that organized life, they also helped groups of people who were not related learn how to get along together. In today's secular cities, it is financial and cultural buildings that dot skylines, and religion and moral cohesiveness are more muted, in part, he says, because families are increasingly less common in major cities. "Who's got time for babies?" he asks, arguing that the high cost of living and small apartments are contributing to low birthrates in some cities.

The challenge for megacities is that they're competing with places that are smaller and more manageable - and from which people can telecommute. With diverse eateries and culture spreading to smaller towns and suburbs, there's less reason to stay in cities, the author argues.

Kotkin has high hopes for places like Des Moines, Iowa, which he says could provide a good urban experience if it continues to blend amenities such as nice restaurants with its middle-class character. He's less impressed with Cleveland, which tried to take the "hip" approach: "They did the Rock and Roll Hall of Fame, they built lofts, they created this kind of new and improved downtown ... [and] what's the result? Poorest city in America, highest percentage of poverty in the country."

Another of his concerns is places with transient populations that build themselves up as centers of culture and entertainment as industry departs. These "ephemeral cities," as he calls them, appeal to the single and the young, but those people will leave when they're ready to settle down, he says."One of the things that worries me is that cities are going to become like giant ... campuses or hotels, [where] somebody will come and use it for a period of time, as opposed to saying, 'This is where I live.' "

The opposite is happening in Las Vegas, for example, where casino workers can afford houses. New residents are also flocking to Phoenix and Charlotte, N.C. "Not what you would call the hip, cool capitals of the world," notes Kotkin.

As for the author, he resides in Los Angeles, where he appreciates living in an urban setting while still having a house with a backyard and trees. "People think of it as Tinseltown, but it's ... a very real city with a big working class, a big poor population, a big middle class."

Kotkin says that with a few exceptions, this is a time of muted vision on the part of city officials, perhaps because the path of cities is currently unclear. "Maybe we're in the early stages of an epoch," he suggests. "It took 30, 40, 50 years into the Industrial Age until we started to correct some of the basic problems."

He suggests that civic leaders follow the example of Julius Caesar - who made Rome, the first megacity, less congested by ordering that the carts crowding the streetsbe used only at night. "You have to understand what the problems are," says Kotkin, "and then you have to have a willingness to act on them."