This is talking about household formation. Basically, the rate at which a population creates people who will demand housing. How they obtain that housing is not a data point. It’s just basically a question of “do you want a place to call your own?” Which is why this article is so full of shit. It’s basically indicating that “if millennials just stopped demanding housing, prices would go down.”

So if a millennial is sitting there in their parent’s house and going “fuck this, I’m getting an apartment”, that’s increasing this value. They don’t actually need to buy a house, they could rent it, that would still be forming a new household.

It just begs the question of what the fuck is this author trying to get at? Should millennial’s parents have been fucking less? Should millennial’s just build a single house commune? Should millennial’s just start offing themselves? This article is a giant pile of boomer bullshit.