I think this is caused by a couple of things. Artificially low interest rates (insofar as the fed rates are artifical) Banks less willing to loan money to any

I think this is caused by a couple of things. Artificially low interest rates (insofar as the fed rates are artifical) Banks less willing to loan money to anyone that doesn't fit a narrow financial profile. Individuals and business with access to existing capital can get money extremely cheaply (see points 1 and 2 above) This creates a stratification that makes it difficult for one group of people to enter the real estate market and easy for another group to enter and speculate in it. The group without access to loans obviously must rent even if they would like to buy. This inflates the demand for rentals thus raising their price. The group with capital/access to loans can buy real estate with the express purpose of renting it taking homes off the market (decreasing supply, raising prices and further pushing up the bar for home ownership). This is even more attractive because of the increased demand and price for rental units. Of course by increasing the supply of rental units this should counteract rental prices but under the current circumstances I think there's a feedback loop that favors rising rental prices and entering/expanding the landlord business.