Economists have been puzzled about why the latest recession produced such a feeble recovery, but here’s one important new clue: The portion of Americans moving from place to place has fallen close to record lows, inhibiting people’s ability to go where the good jobs are or remake themselves in one place after flaming out in another.

Labor mobility, as it is known, has always contributed to the dynamism of the U.S. economy and, usually, to brisk recoveries following an economic downturn. When jobs dry up in one area, people normally migrate to places with more opportunity, which drew settlers to the West in the 1800s, rural citizens into cities in the 1900s, and, more recently, refugees from decaying Rust Belt cities to more vibrant areas in the South and West. This kind of rebalancing is essential in a free market, since wealth moves around and workers must too if they want to pursue it.

But Americans aren’t moving the way they used to. Census data analyzed by demographer William Frey of the Brookings Institution shows that the internal migration rate from 2012 to 2013 was just 11.7%, the second lowest reading since 1948; the lowest was 11.6%, in 2011.

Compare that with an average migration rate of 16.7% in the 1990s. In the 1980s, it was 17.9%, and in the 1950s it was 20.2%. So the portion of Americans moving around in 2013 was barely half what it was 50 years ago. At the same time, the recovery from the 2007-09 recession has been the weakest since World War II, with nearly 20 million people still unable to find a good job and many other adults giving up looking for work altogether.

There are a lot of reasons for the slowdown in mobility, not all of them related to the recession. The U.S. population is getting older, for instance, so young people going where the action is represent a smaller chunk of the population than they did when baby boomers were young adults eager to “follow your bliss,” as philosopher Joseph Campbell urged them to do.

But Americans are also increasingly stuck in place because of economic factors, including some that helped cause the recession. The housing bust, for example, led to double-digit drops in property values in many cities, preventing many homeowners from selling their homes and moving, unless they were willing to bear a big loss. The explosion of debt during the last 25 years has also left homeowners with less equity than in the past, another factor that makes it hard to cut your losses and move to someplace with more opportunity. Recent college graduates may not own homes, but many have onerous levels of student-loan debt, which limits their financial flexibility and may tie them to low-paying jobs that still seem better than the uncertainties a move would produce.