[untog]

> Most Americans have spare bedrooms for when guests visit.

I'd venture that most Americans living in the dense urban environments the OP was talking absolutely do not have a spare room kicking around for guests. Certainly, living in NYC, I don't and neither does anyone I know.

[ajspencer]

I'd venture that this statement also fails in general, not just urban environment. Seems like a very privileged perspective.

[emodendroket]

It's very common in suburban homes to have both an unused guest bedroom and an unused dining room solely for the two times a year the owner entertains. Since this wasn't really logical in the first place I doubt more short-term rentals would make much difference.

[toomanybeersies]

I think it depends a lot on how old you are.

My parents have 3 spare rooms, because my siblings and I have moved out and they haven't downsized to a smaller house.

But I wouldn't expect a young family to have a spare room. When I was younger and we needed a spare room, I was always relegated to the couch to make room for guests.

[ghaff]

I don't expect it's super common to have a dedicated guest bedroom in a house unless it's, as you say, a kid's room who has moved out. On the other hand, quite a few homeowners have a room they use as a part-time office, for hobbies, etc. that has a sofabed in it. That's more or less the case with me. I have a "spare" room that I use for various things but I can make up a bed if I have guests.