The same land is more valuable if regulations permit higher density development.

But trying to suppress land prices by limiting its uses just pushes those price increases nearby.

The most disastrous idea in urban planning is that prices can be kept low by limiting use, and trying to preserve "affordability" for a narrow slice of the middle class. It has failed entirely.

I'm not aware of anywhere that does this? Limitations on use are popular with residents wanting to maintain the character/density of their area.

No one in this thread is proposing that

if you permit more density on a small amount of land, the value of that land will go up. there's only a few places to put the new units, so the good land is scarce, and the price goes up

if you do it over a whole city, i'm not sure it still holds. not as much, anyway, since the developers have more choices on where to build

I'm not sure that's an experiment we'd see unfold due to NIMBYism. (Not commenting on whether that's an appropriate reaction, just that it's inevitable.) So I wonder if within realistic constraints it's still a fairly safe assumption?

the city i'm in has done it up to 4 units. it's pretty recent (less than a year, i think), so i don't expect to see much effect yet

NIMBYs did indeed get involved: you can build up to 4 units in basically any residential zone except for the "rich people" part of town

more cities seem to be doing this sort of thing. hopefully we'll have more/better papers on it in the near future. (and hopefully it works)

But the study looked at detached SFH, not multifamily