The U.S. home ownership rate is at the lowest level in 25 years and is widely expected to go even lower. That's not just the result of younger Americans struggling to make ends meet to save for a down payment on a home. It is increasingly the result of middle-aged, higher income Americans choosing to rent.

Renter growth is now at the highest level in 30 years, and families or married couples ages 45–64 accounted for about twice the share of renter growth as households under age 35, according to a new study by the Joint Center for Housing Studies at Harvard University. In addition, households in the top half of the income distribution, although generally more likely to own, contributed 43 percent of the growth in renters.