[dragonwriter]

> Most Americans have spare bedrooms for when guests visit.

No, they don't. Some Americans do, but it's a minority; most that have a room that loosely serves this purpose have another non-bedroom function for the room that is not significantly impaired by occasional use as a guest bedroom, and a large number, probably a majority, have no guest bedroom at all, putting guests up on a couch (possibly convertible, but maybe not) or temporary cot, etc. in a common room (or displacing a resident, likely a child, to such an arrangement to free up a bed) when hosting overnight guests.