PALM COAST, FLA. -- The recession is claiming yet another victim: Americans' near-constitutional right to pick up and move to a better job.

Labor mobility has nearly ground to a halt in the past two years, and policymakers are increasingly worried that the slowdown is not just a symptom of the nation's economic struggles but also a barrier to overcoming them.

With many people locked in homes by underwater mortgages, only 1.6 percent of Americans moved between states in a one-year period that ended in March 2009 -- a labor stagnation not seen in half a century. Though household mobility has gradually declined for more than two decades, the recent sharp downturn has caused economists to worry that it could harm the already struggling recovery.

"In the past, people tended to move to where the jobs are," said Assistant Treasury Secretary Alan B. Krueger, who oversees economic policy for the department. "Now it is necessary to have more of a strategy to move the jobs -- and create new jobs -- in areas where the people are."

The labor migration rate is down sharply since the start of the economic downturn in 2007 and is just half the rate of a decade earlier, according to William H. Frey, a Brookings Institution demographer who has analyzed Internal Revenue Service and census data.

"Overall, interstate migration has reached its lowest point since World War II," Frey said.

In Palm Coast, civil engineer James Tiffany took a job in 2006 and quickly bought a home to capitalize on the boom that transformed this once sleepy retirement community into one of the nation's fastest-growing cities.

But as boom turned to bust, Tiffany was thrown out of work, and the city became known less for its explosive growth than its alarming level of joblessness. The area's unemployment rate is 15.4 percent, the nation's 11th highest, and many of the jobs that once powered the local economy are probably gone for good.