AMERICANS are supposed to be mobile and even pushy. Saul Bellow’s Augie March declares, “I am an American ... first to knock, first admitted.” In “The Grapes of Wrath,” young Tom Joad loads up his jalopy with pork snacks and relatives, and the family flees the Oklahoma dust bowl for sun-kissed California. Along the way, Granma dies, but the Joads keep going.

But sometime in the past 30 years, someone has hit the brakes and Americans — particularly young Americans — have become risk-averse and sedentary. The timing is terrible. With an 8.3 percent unemployment rate and a foreclosure rate that would grab the attention of the Joads, young Americans are less inclined to pack up and move to sunnier economic climes.

The likelihood of 20-somethings moving to another state has dropped well over 40 percent since the 1980s, according to calculations based on Census Bureau data. The stuck-at-home mentality hits college-educated Americans as well as those without high school degrees. According to the Pew Research Center, the proportion of young adults living at home nearly doubled between 1980 and 2008, before the Great Recession hit. Even bicycle sales are lower now than they were in 2000. Today’s generation is literally going nowhere. This is the Occupy movement we should really be worried about.

For about $200, young Nevadans who face a statewide 13 percent jobless rate can hop a Greyhound bus to North Dakota, where they’ll find a welcome sign and a 3.3 percent rate. Why are young people not crossing borders? “This generation is going through an economic reset,” said John Della Volpe, who directs polling at Harvard’s Institute of Politics, which surveys thousands of young people each year. He reports that young people want to stay more connected with their hometowns: “I spoke with a kid from Columbus, Ohio, who dreamed of being a high school teacher. When he found out he’d have to move to Arizona or the Sunbelt, he took a job in a Columbus tire factory.”