The average rent in San Francisco is more than $3000 a month. In New York, you’re paying $2,355.  

According to the real estate tracking firm Zillow, rents are up 3.7 percent, nationwide.

“More and more Americans are renting now than they did before the great recession,” says Zillow senior economist Skylar Olsen.  

Olsen says there just isn’t enough rental housing to go around.  She says the renters are former home owners who were foreclosed upon, or newly employed millennials.

“They’re able to you know, imagine a world where they move out from their parents’ basements,” she says. “And when they do that they turn to the rental market.”

They can’t afford to buy a house because, even though they have a job, wages are still stagnant.

“Brad Pitt’s making millions of dollars but the average person in Keokuk, Iowa is not making a lot of money in terms of wage growth,” says Anthony Sanders, distinguished professor of finance at George Mason University.

And Sanders says, even if they do have a nest egg, they’re too nervous to buy in the wake of the housing crisis.