One reason this group is staying in cities might be that they can’t afford to leave, according to William Frey, a demographer at the Brookings Institution. Millennials often don’t have enough money saved up to consider buying a house somewhere else—let alone covering the moving costs to get there or possibly suffering a pay cut or taking on a less thrilling job.

This isn’t how it used to be. In previous decades, cities like New York and Los Angeles attracted twentysomethings with educational or professional opportunities, and then those twentysomethings would migrate to places where they could settle down with a family and buy a spacious house after a few years in the city. This geographic dispersal of highly-skilled workers, the norm for decades, meant that the gains of states with stronger economies could be spread to those with weaker ones.

It’s easy to assume that Millennials love cities simply because so many of them live there, but it looks like a majority of them, after a stint in a city, still yearn for the same thing their parents pursued: a single-family home in a suburban neighborhood. A survey by the National Association of Home Builders released last week called on about 1,500 people born after 1977. Sixty-six  percent of those respondents said they wanted to live in the suburbs, versus the 10 percent who wanted to live in a city.