The economy is booming, but Americans still aren't moving

"It's surprising because we have kind of a booming economy, and it's a time you would think mobility would start picking up."

The big picture: Mobility rates have been falling more or less steadily since the 1980s. The trend can be explained partly by the aging U.S. population, since older people tend to move around less, Lawrence Yun, chief economist and senior vice president of research at the National Association of Realtors, told Axios.

The surprise, he said, is that mobility trends have continued to fall over the past few years, given the recovering and even booming economy.

• The biggest decline has been in the share of Americans moving within the same county, falling by 2.4 percentage points since 2005. However, it remains the most common kind of move.
• Millennials could also be playing a role in the more recent downturns, according to Frey, as 25- to 34-year-olds are far more likely than past generations to live with their parents and less likely to own homes or move around. The decline in mobility rates has occurred across all age groups, however.
• Geographical trends have remained the same, with high migration toward the Sun Belt and more immigrants leaving than arriving in the Northeast.

The impact:

• The housing sector suffers most from the falling mobility, Yun said, as there are far fewer home sales when people aren't moving.
• It could also hurt infrastructure, since local governments could have less incentive to improve it if people aren't moving away to areas with better economic opportunity. "If there's greater mobility, there would be more competition," Yun said.

The bottom line: "Three years ago, I thought it would be a low point and I thought we would turn the corner," Yun said. We haven't — and it's clear that we don't know all the reasons yet.