Migration around the U.S. slowed to a crawl last year, especially for this decade’s boom towns, as a weak housing market and job insecurity forced many Americans to stay put.

Demographers say the dropoff in migration, shown in Census data to be released Thursday, is among the sharpest since the Great Depression. It marks the end of what Brookings Institution demographer William Frey calls a “migration bubble.”

As asset values rose fairly steadily in the past decade, Americans young and old moved around the country in search of jobs or better weather. In many cases, people living in higher-cost housing markets such as San Francisco and New York cashed in their real-estate winnings and moved to outlying counties, or to states like Florida and Nevada, hoping to find a cheaper house and pocket the difference. Now, “people are hanging tight; they’re too scared to do anything,” said Mr. Frey.

The data, covering the one-year period until July 1, 2008, show this effect across U.S. counties and metropolitan areas — another sign of how this recession has spared few industries or regions.

Migration typically slows during recessions. But in past downturns, the slowdown has been more regional in scope, with workers fleeing weaker job markets for places where companies were still hiring. In the deep 1980s recession, for instance, laid-off auto workers fled the industrial Midwest for energy-rich states in the South with more plentiful jobs.

What’s unique this time is migration has slowed almost everywhere. The sharpest year-to-year changes were among what demographers call “domestic migrants,” people who moved within the U.S. That doesn’t count population changes that result from births, deaths or immigration.

Older metro areas such as New York and San Francisco, which have seen residents move to faster-growing areas, are now losing fewer people. Cities in the formerly hot housing markets such as Nevada and Florida are seeing fewer arrivals and, in some cases, more people moving out than in.

At the local level, more people are staying in the city and postponing their move to the suburbs. In 2005-06, metropolitan areas with one million or more people saw a net 688,000 people leave their core counties. In 2007-08, a net 336,000 left, according to an analysis of Census data by Kenneth Johnson, senior demographer at the University of New Hampshire’s Carsey Institute.

“Fewer people are leaving the urban cores to go to the suburbs,” said Mr. Johnson.

International migration slowed moderately, according to the Census data. In 2005-06, the country absorbed a net of about one million immigrants. In 2007-08, that fell to a net gain of 890,000. The slowdown in international migration was sharpest in outer suburban areas, where the housing market has in general been worse than in core cities or closer-in suburbs.

The slumping economy, as well as depressed prices of just about every kind of asset, is behind many of these decisions to stay put. Jeff Fallon, a managing partner at a private-equity firm in Cleveland, made two trips to Florida last year looking to buy a home in the Sarasota area. But with the stock market down and real-estate prices still falling, Mr. Fallon decided to hold off for a bit.

“I was looking at a substantial amount of our personal wealth disappear as the stock market spiraled down,” he said. “It certainly had a lot of bearing on whether or not I was willing to invest in a second home.”

If the migration slump continues, it could slow down economic recovery in depressed housing markets such as Las Vegas.

Decisions like his help explain why a net 15,000 people left the Cleveland area for somewhere else in the U.S. in 2007-2008, compared with a net of 21,000 between 2005 and 2006. Sarasota, meanwhile, saw a net increase of 2,500 residents from inside the U.S., compared with as many as 20,000 during the boom years.

The Census data show that the biggest falloffs were in the worst housing markets. In 2007-2008, the Phoenix area gained a net 51,000 domestic migrants, about half as many as two years ago.

Las Vegas increased by a net 14,000 domestic migrants, two-thirds fewer than two years ago. California’s Riverside-San Bernardino metro area, a once-booming market that has been hammered by foreclosures and job losses, lost domestic migrants for the first time since 1995-1996.

The migration slowdown, if it persists, could further delay the economic recovery in depressed housing markets such as Phoenix and Las Vegas. These places generally have a larger amount of unsold homes, and a disproportionate share of the economy is dependent on construction and other real estate-related trades.

Economists say the housing-centric economies will need to reduce their stock of unsold homes before any meaningful economic recovery takes place. That’s hard to do when fewer people are moving there.

BEIJING — The World Bank cut its forecast for China's growth this year to 6.5%, below Beijing's target of around 8%, and cautioned that China should be prudent about expanding its stimulus this year as it may need to save its ammunition for 2010.

The bank now projects China's consumer price index, the country's key inflation gauge, will rise a mere 0.5% this year, compared with its previous forecast for a 2% increase.

The bank said February's CPI drop didn't necessarily signal "problematic" deflation, with core prices and wages, as well as output, declining in tandem, but cautioned that given the global economic weakness and potential overcapacity in China, "problematic deflation is a risk."

The bank lowered its forecast for China's GDP growth from its previous estimate of 7.5%, mostly due to the worsening global economy.

Government investment and consumption will help growth this year, it said. But policy makers can do more to spur private consumption and improve social programs to ensure that short-term growth targets don't undermine the work needed to rebalance the world's third-largest economy, the World Bank said.

Louis Kuijs, senior economist of the World Bank, said China's year-to-year economic growth will likely be weakest in the early part of 2009. Mr. Kuijs said declines in Chinese exports may have bottomed in February, but full-year exports will likely shrink significantly from last year. "Overall they remain very grim," he said.

Chinese exports in February fell 25.7% from a year earlier, down for the fourth month running and a sharper decline than in January.

Mr. Kuijs said it is not in China's interests to significantly depreciate the yuan as the country will not gain a lot in terms of exports by doing this. He said he doesn't expect China to move in this direction.

The bank said government-influenced direct expenditure will account for 4.9 percentage points of total GDP growth, the bank said.

The bank said China's fiscal deficit will rise to 3.2% of its GDP this year, a forecast slightly higher than the Chinese government's own estimate of nearly 3% due to the bank's lower GDP growth forecast.

Much of China's deficit is a result of the government's four trillion yuan (around $585 billion) infrastructure-focused stimulus plan, which was announced in November and will run through 2010.

The bank said that Beijing should be prudent about further expansion of its fiscal stimulus this year as it may need to widen its deficit in 2010 if the global slowdown isn't reversed.

Mr. Kuijs urged China to focus more on consumption-oriented fiscal spending and improve the domestic social safety net.

"Looking ahead, we think that there are limits to how much the government can beef up investment and infrastructure-oriented stimulus packages in the official manner," he said. "Given that China will continue to grow even in the very weak climate, it may make just as much sense to not go for the second or third general fiscal stimulus."

The bank's new overall growth rate estimate is below Beijing's target of around 8%, and down from last year's actual growth of 9%, which snapped five straight years of double-digit growth in China.

But the World Bank said that while the growth rate projected for this year is "significantly lower" than China's potential growth rate, this isn't likely to jeopardize China's economy or social stability.

"I don't want to be too gloomy. We do see the world economy recovering in the second half of 2009 and also a lot of strength in China's economy," said David Dollar, the World Bank's country director for China. "So, we see China as a relative bright spot in a rather gloomy global economic picture."

The World Bank estimated China's foreign-exchange reserves, the world's largest, will rise to $2.376 trillion by the end of this year, an increase of $425 billion. In 2008, the country's forex reserves rose by $420 billion.

It said China shouldn't worry about the slowing pace in the accumulation of foreign-exchange reserves and estimated China's current account surplus to rise to $425 billion this year, from an estimated $416 billion last year.