These data points represent not so much a shifting from one power center to another but rather a change in how financial power is distributed. In this decade, the global economy has become multipolar. “On the one hand, we have tremendous strengths,” says Robert Rubin, the former Treasury secretary and now chairman of the executive committee at Citigroup. “We’re located in the largest economy in the world. On the other hand, London is creating a regulatory environment that seems to me is equally as effective in terms of safety and soundness. Hong Kong and Singapore are clearly determined to develop as centers. The Chinese are investing in Shanghai.”

Like automakers and consumer-products companies (Coca-Cola derives 70 percent of it sales outside North America), New York’s leading financial institutions are trying to become global operators less reliant on domestic markets. In the last few years, the N.Y.S.E., the iconic symbol of Wall Street, has gone public, hired an aggressive, worldly C.E.O. (the former Goldman Sachs president John Thain) and merged with Euronext, which owns a derivatives market in London and stock exchanges in Paris, Brussels and Amsterdam. In its most recent quarter, NYSE Euronext derived 44 percent of its revenue and 62 percent of its operating income from outside the United States. Nasdaq, the second-largest New York exchange, was thwarted in its bid to buy the London Stock Exchange, but is taking a stake in OMX, which operates stock exchanges in Nordic countries in partnership with a Dubai investment firm.

The big investment banks closely identified with New York are increasingly international, too. Goldman Sachs recently boasted that half of its revenues came from overseas. Overseas growth is good for shareholders and managing directors, who share in the profits. But an alliance with a Chinese investment bank doesn’t necessarily translate into jobs for the messengers and support staff at Goldman Sachs in New York.

What does all this diffusion mean for New York’s economy? Potentially, a great deal. Steve Malanga, senior fellow at the Manhattan Institute, estimates that there are 175,000 securities-industry jobs in New York, which pay an average wage of $350,000. The Committee on Capital Markets Regulation notes that the securities industry accounts for 4.7 percent of the jobs in New York City but 20.7 percent of the wages. But the impact is even larger, since the spending of Wall Street hotshots supports a huge number of other jobs. Between 1995 and 2005, the sector grew at an average annual rate of 6.6 percent in New York and provided more than a third of business income-tax revenues, according to McKinsey. “There’s no doubt that much of the financial and fiscal and economic revival of the city in the 1990s and then again after 9/11 can be attributed to the health and in fact dominance of Wall Street internationally,” Malanga says. A long-term decline, in which the financial-services business slowly moves offshore or out of state over a period of years, would certainly inflict great damage. Without a manufacturing base, New York would become more dependent on its other large sectors like tourism, health care, government and education, none of which possess Wall Street’s capacity for spinning enormous profits.

It seems inevitable that we will see many more studies about the loss of New York’s status. Unless they can persuade Congress to stop globalization and the free flow of capital around the globe, there isn’t much New York’s billionaire financiers can do to stop the city’s relative decline.

Because of the high costs of living and doing business in New York, the city is likely to continue to lose market share. Take the case of BATS, an alternative trading platform based in Kansas City, Mo., that has come out of nowhere to gain a 9 percent share in the market for trading United States stocks. “Our location is one of the principal factors that enabled us to go from start-up to the third-largest equities exchange in the U.S. in a matter of 18 months,” says Joe Ratterman, its president and chief executive officer. The company’s computers reside in a New Jersey data center, and it has two sales representatives in New York. But the rest of its 33 employees work out of a 10,000-square-foot office complex with views of downtown Kansas City. In a business in which competition is based on cost — BATS appeals to investors looking to save a few pennies on trades — a start-up in low-cost Kansas City has the same advantage over the N.Y.S.E. that a Chinese manufacturer does over a competitor in Ohio.

Image Credit... Illustration by Hort

New York has stood at such inflection points before and survived. “Between 1860 and 1920, the economy changed several times, from agricultural to industrial, and from industrial to financial,” says Thomas Kessner, author of “Capital City: New York City and the Men Behind America’s Rise to Economic Dominance, 1860-1900.” “And each time, New York City was able to take advantage of the position it had achieved in previous standing and leverage that into leadership in the new era.”