America used to be the mobile society. People would pick up and move to the next opportunity or adventure. Oregon Ho! Sure, moving could be scary - failure was always a possibility - and yet we took that risk time and again. Then we stopped. What happened?

The risk/benefit calculus changed. For one thing, marital bonds became less reliable. She/he couldn't be depended on to be there through thick and thin. Even if unacknowledged it, the tenuousness of modern relationships leaves it mark on our Big Decisions. After leaving friends and family, you might wind up left on your own in the new promised land. Gives one pause.

More prosaic factors are at work as well. Occupational licensing has become out of control. Close to a third of American workers have to get state-mandated licenses to do their jobs. We're not just talking lawyers and therapists but florists, tour guides, even hair-braiders. So cross-state mobility really takes a hit. And in the really desirable locations, the locals have made it clear they don't want you. They votes for politicians that put in place zoning restrictions limiting the supply of housing, making it unaffordable in the bargain. Welcome to San Francisco - enjoy your visit.

So Americans stay put more than they used to. This partly reflects better circumstances overall - few of us will starve unless we get the hell out of here. But it also reflects fear and a preference for safe havens. Worse, it reinforces political polarization and increases income inequality. We stay where it's comfortable, surrounded by people like us.

Actually, not all Americans are stuck in their geographical rut. The college educated are still a mobile lot. It's the less educated that are more likely to stay put. Makes sense - moving is an expensive leap of faith and it's a riskier proposition for the marginally skilled or credentialed.

Economist Enrico Moretti has an excellent idea for getting more Americans on the move: provide mobility vouchers to supplement unemployment benefits for recipients living in areas with above-average unemployment. Such vouchers would benefit both the leavers and the remainers.

As Moretti puts it:

…by increasing the number of workers willing to relocate, mobility vouchers would benefit both those who leave and end up with a better job elsewhere and those who stay and end up with a better chance of finding a job.