Mayor Michael R. Bloomberg has promoted himself as a model of fiscal restraint, issuing dire warnings about the slowing economy, recently asking agencies to limit hiring, and even listing “fiscal responsibility” as an interest on his MySpace page.

At the same time, a review of the city’s budget since 1980 shows that Mr. Bloomberg has been presiding over one of the greatest expansions of city government since the John V. Lindsay administration, fueled by an extraordinary surge in real estate revenues, both from higher property taxes and transfer taxes from sales.

Since Mr. Bloomberg took office in 2002, the city budget, adjusted for inflation, has swelled faster than it has under any other mayor during the last 27 years, increasing by 23 percent, to $60 billion.

By contrast, spending rose 8 percent during Mayor Rudolph W. Giuliani’s eight years, and 4 percent under Mayor David N. Dinkins, who served one four-year term. Mr. Bloomberg’s spending also outpaced that of Mayor Edward I. Koch, who increased the budget by 19 percent over his last two terms.

No one is predicting a collapse of the city’s fiscal stability as a result of the increased spending, and Mr. Bloomberg, who is scheduled to speak about economic policy to Britain’s Conservative Party at the end of the month, generally receives high marks for his stewardship of the budget.

But some worry that New York, along with other cities where the real estate market has been hot, is ill-prepared to grapple with a downturn, having grown accustomed to booming revenues from flush times.

According to the mayor’s Office of Management and Budget, approximately 75 percent of the growth under Mr. Bloomberg has been driven by expenses that are difficult to control, like employee health care costs and benefits, pension payments and Medicaid.

But Mr. Bloomberg, who declined to be interviewed for this article, has also significantly increased more discretionary accounts, reflecting his emphasis on quality-of-life issues and his desire to make New York attractive to people and businesses. Spending on parks, often one of the first areas to lose money in lean times, jumped 27 percent over his tenure, to $298 million, for example. The budget at Information Technology has almost tripled to $157 million, largely due to establishing the city’s popular 311 service hot line and to upgrading other technology systems.

Spending on schools jumped 14 percent, to $16 billion, driven by a 40 percent increase in teacher salaries favored by Mr. Bloomberg, among other expenses.

And although the number of city workers has declined by about 1 percent since Mr. Bloomberg took office, he has been increasing the staff of late, adding nearly 10,000 workers since 2004, bringing the total up to 367,643.

City officials argue that their approach has been restrained, and that the mayor’s investment in services has helped the city thrive, bringing about a still-declining crime rate, cleaner streets and safer traffic conditions.

“Any way you look at it, city government has functioned well over the last almost six years,” said Edward Skyler, the deputy mayor who oversees the budget. “And the resources the mayor has allocated have been well spent.”

The New York Times examined overall city spending as reported by the Independent Budget Office, including state and federal aid, dating back to 1980, the earliest year for which reliable records are available. The spending increases described in this article have been adjusted for inflation.

Of the $60 billion spent in the last fiscal year, $16 billion came from state and federal sources, a smaller percentage than in 2002.

When Mr. Bloomberg took office, he inherited a budget punch-drunk from the aftereffects of 9/11 on an already slowing economy, facing a $5 billion deficit in what was then, in 2002 dollars, a $41 billion budget, including $14 billion from Albany and Washington. The mayor spent his first months in office looking for ways to reduce spending through cutting staff and modestly trimming services, but he increased revenue through borrowing and eventually raising taxes, fines and fees.

“He very deliberately, early on, made the choice that rather than really jamming down services, he was going to hold the service level and raise taxes,” said Mark Page, director of the Office of Management and Budget. Mr. Bloomberg has also personally contributed tens of millions of dollars to the city, forgoing his salary, paying his own travel expenses, donating to social service and cultural groups whose city grants he trimmed, and supporting projects and experimental programs.

Since then, Mr. Page added, the growth in population and the economy has led to “a major increase in revenue that has enabled us to cut taxes and spend more. Smaller class sizes, dividing up large schools, maintaining parks, cleaning streets, what-have-you are all things that people like and they all cost money.”

James Parrott, chief economist of the Fiscal Policy Institute, a left-leaning research group, said this dynamic was at work in 2003, when the mayor pushed through an 18.5 percent property tax increase. The mayor and City Council agreed to reduce property taxes by 7 percent for this fiscal year.

“He was very clear at the time, saying we can’t just slash public services, because we did that in the fiscal crisis and we’ve been paying for the damage for a long time,” Mr. Parrott said.

Although the rise in revenues is overwhelmingly due to growth in the economy, roughly 15 percent of the increase resulted from Mr. Bloomberg’s imposition of new taxes and fees, primarily the property tax increase, according to an analysis by the Independent Budget Office, a publicly financed research and policy agency that does not report directly to the mayor.

“He does look to the revenue side to meet needs,” said Charles Brecher, research director at the Citizens Budget Commission, a business-backed research group and a co-author of “Power Failure,” which studied New York politics and policy from 1960 to the early 1990s.

“It’s not that he’s necessarily taken on new roles for government, but he’s put money into education, he’s paying people more, and there has been selected expansion in some services.”

Many fiscal experts applaud the mayor’s use of recent windfalls to pay down spiraling long-term expenses, such as future interest on debt and pensions.

Still, some analysts see a danger in ever-rising spending based on volatile sources that are eventually bound to decline, like the financial or real estate markets.

“You’ve continued expanding a government that’s tuned to run on high-test — it basically wants to grow at a certain level,” said E. J. McMahon, a senior fellow at the Manhattan Institute, a conservative research organization. “It creates unsustainable appetites among all the major consumers of city tax money, and you’re still not fixing infrastructure.”

The spending also underscores Mr. Bloomberg’s belief in the power of government to solve problems, a notion that runs counter to the small-government rhetoric of the Republican Party he abandoned in June.

Ester R. Fuchs, a political science professor at Columbia University who was a special adviser to the mayor in his first term, said that Mr. Bloomberg’s spending pattern represents a new strategy for keeping cities healthy and competitive.

“He was never antigovernment,” Ms. Fuchs said. “He actually viewed government as having a role, and by making government both more responsible and efficient, he made people more comfortable with the idea that government could spend the money effectively.”

Read article here