A number of people I know are involved in such relationships, where an older woman lives with or very close to a coterie of male companions with whom she has sex. All are very happy with the situation and none are harem-like (in all cases all participants are economically independent). How common is this arrangement?
I have no clue on your question. But …
As people get older, the men die off earlier on average and the women become an ever-increasing majority as everyone ages. I’ve heard rather the opposite situation to the OP occurs in most retirement communities, independent living places, etc.
At age 70-mumble there are, e.g., 5 single women for each single guy. Many of these guys do better with the ladies than they ever did in college.
My husband is still very much alive, but should he die before I do, I seriously doubt that I’d want a stable of young studs, unless it was to do yard work and household repairs. I don’t claim to be typical, but I’ve never encountered the situation described in the OP.
I should have been clearer: the men are all similarly aged. No young studs.
How many people do you actually know who live in this sort of arrangement?
You will find quite a few older women described as serial daters on some of the online dating web sites. The local bars seem to have their share of them as well.
Maybe the men in this scenario are good for once a week, but she wants it once a day.
According to my research consisting of episodes of “The Golden Girls” and “Who’s the Boss?” this is extremely common.
In that case, I’d be even less inclined. Old guys are all falling apart - who needs that??? 
Seriously, tho, among my older, unattached friends (we’re all late 50s, older 60s) the women seem to be quite content without and men in their lives. Even the one who, as a young woman, always had lots of guys around her. Granted, it could just be that we all have similar attitudes and that’s why we’re friends.
I don’t know anyone living in this kind of arrangement, but that’s not to say that it may be more common than we think. Most of my menopausal and post-menopausal friends are not very interested in sex at all. I’m 52 - and post-menopause (it came early for me). I hope to have sex until I die.
I know a double digits worth of polyamorous families (and more poly folks who aren’t plural in living arrangements)…and I’ve never seen this one. I don’t think it’s very common. But of course it’s the kind of thing that’s unlikely to be openly announced to the public at large, so I’m sure it happens more than I think. It’s the least common of the poly permutations, though, I’m pretty confident in that statement. Poly is more common in younger people than old, and more commonly polygyny than polyandry in cohabitating cohorts. The two together, the math gets small.
As far as you’ve observed, is this limited to Scotland?
I know a bunch of polyamorous families, etc., too, but they are mostly younger than that. I don’t really know the intimate details of the lives of many women much past menopause.
No, it isn’t limited to Scotland.
What a way to go, although what a downer for your partner(s).
I’ve known one serial dater in her 60s and 70s, but on the overall it doesn’t seem to me to particularly common, although of course it’s not like I’m kept updated about the sex life of every individual old lady I know.
Still, I’m unconvinced that the situation described by the OP is very usual. We’d probably hear about it if it were that common.
Bummer.
Up until now it sounded like a nice arrangement.
Perhaps, but should the partner(s) finish?
Ain’t gonna matter to her either way. 
:eek:
I’m enjoying the jokes. Perhaps I should’ve worded that a bit differently, eh? English is my second language. I blame it on that!