I think it should be 17M (12%), I tried plotting it in FRED: https://fred.stlouisfed.org/graph/?g=mGVF (the numbers themselves from the US Bureau of Census) The highest the US has gone recently is 15% vacant housing units, and it's been going down since the Great Recession. I think one reason why 12% is not so unbelievable is that if people move reasonably often, and it takes a certain amount of time to find a new tenant, then part of the vacancy rate will be proportional to the rate of churn of people moving in/out. For a single landlord, a 12% vacancy rate is about 1.5 months of rent missing per year, which is high but not hard to imagine.
Looking at that plot, it does seem like the vacancy rate correlates with housing bubbles quite well.
Like a lot of stats, one has to sit back and think of the definition and not let intuition or feelings get in the way. I can't comment on whether that is or isn't high, but I've got some experience trying to calculate such in Australia. You've got to take into account:
- abandoned yet still livable homes
- new construction not yet moved into
- houses currently in the state of being sold
- old buildings not yet demolished
- airbnb and short term rentals currently sitting empty: seasonal housing usually makes up a large extent of vacant housing in a country
- accomodation for workers/fly-in-fly-out workforce
- rentals currently vacated because they can't find a tenant
- rentals currently tenanted but not being occupied (because of moving in/out consecutively with other properties)
- holiday homes not being used
The Aussie census also calculates about 11% of homes being vacant on census night.
Like with employment markets, most people seriously underestimate the true 'state of natural churn' in these stats that can be found in a modern day country/economy, and just form a picture in their head of an apartment block just sitting there doing nothing all the time or wonder why people aren't being housed in them.
I know this stuff can be highly market dependent, but that roughly matches on-the-ground observation in Midwest. (11% of homes are vacant, rental units have a ~9% vacancy rate).
Some of those houses are in disrepair (unlivable). Some of the units are brand new (not yet occupied). Some are bank owned investment properties (intentionally empty). Some are between occupants. Etc.
https://www.statista.com/statistics/183635/number-of-househo...