Millennials are "less mobile" than any of the previous four generations, according to a new report. That doesn't mean they sit on the couch and Snapchat all day. Nor does it have anything to do with their mobile phones. They just aren't moving from where they live.

Millenials watch a video calling on the millennial generation to help end the problem of extreme poverty around the globe at the IMF/World Bank Group's Spring summit on April 10, 2014. Miguel Juarez Lugo / Zuma Press file

According to a Pew analysis of recently released Census Bureau data, only 20 percent of respondents aged 25-35 said in 2016 they had lived at a different address than the year before. That's lower than the career-minded Silent Generation, inwardly focused baby boomers, and independent Gen Xers. "When I was your age..." a member of one of those groups might begin, "we had a one-year migration rate of 25 percent or above..."

That might seem counter-intuitive, since millennials are less likely to be tied down by three of the biggest things that tend to hinder people from moving — a spouse, a house, or a child — compared to those previous generations, according to Pew research.

You could blame it on this generation rejecting norms, needing to be coddled, spending too much time staring at screens — any handy scapegoat will do.

But the answer becomes clear when you follow the money: They don't have it.

Since 2010 there are fewer currently employed 18-24-year-olds (54 percent) than at any time since the government started collecting data in 1948. And there's a wider employment gap between young and all working-age adults than at any time in recorded history.

It's not that they don't want to participate in the economy. There's just less of it for them to join. Without a job to move for, why wouldn't you stay close to home?