Why isn't Philadelphia Boston? Why does Boston prosper, people and businesses outbidding one another to get in, while Philadelphia languishes, with acres of vacant and underused property announcing the lack of local demand? Why does much of Boston look like Hollywood's idea of a hip, fabulous place to live, while downtown Philadelphia seems to be a bleak postindustrial landscape--the few good buildings that are still standing routinely visited by street people begging at their entrances?

The answers are not to be found in conventional 20th-century analysis, which emphasized the seemingly unsolvable urban crisis: the decline of industrial jobs, the burdens of excessive taxation, the inevitability of racial tensions and the dominance of geography. After all, in traditional urban terms, Philadelphia and Boston are nearly twins, both founded by Protestant-Anglo stock in the 17th century, both blessed with prime locations, beautiful waterfronts, good vernacular housing, historic buildings, Olmsted parks, renowned museums and fine universities. And both are high-tax cities that have lost their industrial base. Yet one now thrives while the other declines.

At least part of the answer stems from their underlying cultures. In his "Puritan Boston and Quaker Philadelphia" (1979), E. Digby Baltzell argued that Boston Brahmins, with their belief in authority and leadership, embraced a sense of responsibility for civic life, while Philadelphia Gentlemen, with their inward but judgmental Quaker ways were deeply unconcerned about their city's welfare. Over the course of the 19th century and well into the 20th, they abdicated their role in government and watched indifferently as Philadelphia became, by the 1960s, the worst run city in the nation. The Brahmins might have been intolerant and unpleasant while the Philadelphians were open and charming, but the Brahmins cared about their city--and so, subsequently, did the Irish politicians with whom they warred and the Italians who replaced the Irish.
Such cultural analysis--long out of fashion as too soft (as as opposed to econometrics) or too racist (who is to say that one culture is better than another?)--is due for a comeback. It starts to explain, in a way that mere fiscal analysis does not, why Miami has become the gateway to Latin America, why Los Angeles rules the Pacific Rim and why Chicago controls the Midwest. And it helps us to understand how New York City moved in 30 years from the humiliation of near bankruptcy to being the dominant city on earth.

The old answer of urban success was deterministic: taxes and geography. Cities with superb natural harbors, for example, become the natural capitals of trade, commanding and distributing the resources of their hinterlands. They kept their own taxes low by feeding off their interiors. Yet as the historian Richard Wade has noted for years, against the tide of his field, this theory has its flaws: If the sheer excellence of a harbor truly determined a city's fate, then the greatest city in America would be Upper Sandusky, Ohio.
What flourishing cities often have in common, instead, are two crucial cultural characteristics: combativeness and cunning. New Yorkers, for example, fought back from their 1975 bankruptcy with every tool at their disposal, fair and unfair. Their rallying cry against the federal government--the famous Daily News headline of "Ford to City: Drop Dead"--had never actually been said by feckless President Ford. Indeed, on the merits, the Ford administration had good arguments for resisting a bail-out of the nation's financial capital.

Yet New York armed itself with brilliant leadership, cut its bloated operating and capital budgets, cajoled the federal loan guarantees from Congress, poured money into fixing up thousands of units of abandoned housing, fought crime and graffiti--and emerged triumphant. It might have done even better: It barely reduced its onerous tax burden, regarded by many analysts as the highest in the country. Indeed, one of New York's most notorious, anti-enterprise taxes is the 4% unincorporated business tax, which was targeted at wealthy physicians but which instead hits every bodega and small business. Surely this tax has done serious harm, if not enough to force its repeal. Somehow New York's entrepreneurial spirit drives forward, scattering even the grossest of obstacles--almost against reason.

That same energy contributes to New York's cyclical boom-and-bust nature, regularly pushing speculation beyond the limits of an exuberant boom, thereby encouraging a bust. New Yorkers have done this for centuries while, for example, more temperate Chicagoans have not. Seemingly more stolid than New Yorkers, Chicagoans have transformed Carl Sandburg's brawling city of big shoulders into what is probably the most beautiful of postindustrial cities.

Chicagoans actually think about beauty in a way that New Yorkers do not, caring for their public gardens--which go unvandalized though they are also unpoliced--and embracing Mayor Daley's seemingly quixotic decision, 20 years ago, to put flowers wherever he could fit them, starting with highway barriers. (At the time, New York's parks commissioner, Gordon Davis, complained that he couldn't even get his own staff to plant flowers in front of his headquarters.) Cherishing their unparalleled lakefront--originally a gift of businessman Montgomery Ward--Chicagoans keep it free of invasive development while encouraging towers for the wealthy to rise efficiently behind Lake Shore Drive.

When a public consensus developed, in the second Daley administration, that the southern section of the drive was too close to Lake Michigan, Mayor Daley's people simply relocated it inland--revealing even more of their splendid lake without hurting traffic. Such a move would have been unthinkable in more contentious New York, where the congested and ugly West Side Highway still blocks the Hudson River waterfront--and the memory of the proposed above-ground Westway, stopped in the 1970s, can still induce room-clearing arguments.

Cunning and combativeness, however, often restore cities financially without making them many new friends, except, perhaps, for the young--who, for the past two decades, have been returning in great numbers to the old neighborhoods long ago abandoned by their parents and grandparents. So widespread yet diverse is the youth wave that it has produced well-known derisory terms like yuppies, buppies and guppies--terms that played down the significance of their achievement. Returning youngsters played for a few years, then settled down to buying houses, raising children, fighting for better schools and reclaiming their lost urban heritage.
But what makes cities successful--or even just lovable--can seldom be quantified. Even Baltzell, who admired the mind and achievements of Puritan Boston, said that his heart and loyalties were rooted in Quaker Philadelphia, which he criticized so harshly. As poet Phyllis McGinley wrote, perhaps in astonishment, "Some love Paris and some Purdue."

Ms. Vitullo-Martin is a senior fellow at the Manhattan Institute.