OK Boomer, Who's Going to Buy Your 21 Million Homes?

One in eight owner-occupied homes in the U.S., or roughly nine million residences, are set to hit the market from 2017 through 2027 as the baby boomers start to die in larger numbers, according to an analysis by Issi Romem conducted while he was a senior director of housing and urban economics at Zillow. That is up from roughly 7 million homes in the prior decade.

By 2037, one quarter of the U.S. for-sale housing stock, or roughly 21 million homes will be vacated by seniors. That is more than twice the number of new properties built during a 10-year period that spanned the last housing bubble.

Most of these homes will be concentrated in traditional retirement communities in Arizona and Florida, according to Zillow, or parts of the Rust Belt that have been losing population for decades. A more modest infusion of new housing is expected in pricey coastal neighborhoods of New York or San Francisco where younger Americans are still flocking in large numbers.

On the face of it, this doesn't sound all bad. Dying homeowners have always needed to be replaced by younger ones and the U.S. has for a number of years suffered from a shortage of housing, a development that has dampened recent home sales activity and kept many millennials stuck in rentals.