In a very interesting post, Francis Morrone suggests rhetorically:
"Now, we are all supposed to hate gentrification."
But we don't.
Because we keep doing it.
And it's basically a very good thing.
And even if it isn't, we'll keep doing it.
Because, ultimately, you cannot stop a free market unless people essentially agree with the social premise behind the regulation. Rent-control's "key money" -- under-the-table transfer of a rent-controlled tenancy -- is a prime example that when people value things more than the law is supposed to allow them, then they find their way around the regulations by what becomes illegal transactions. The free market prevails except when there is a very broad social consensus that the regulation is appropriate (e.g. child labor laws.)
That's part of the issue with gentrification, at least in cities where the housing stock at issue is primarily owner-occupied single-family detached: What could really be done to stop it? At the same time as one is arguing about whether it's a good thing or a bad thing, consider whether it is amenable to social control at all. I'd suggest that gentrification is far too organic and natural a social process and is largely beyond social control, unless one wanted to bring back racially-descriminatory laws.
Even if one wanted to, and I certainly do not, what could one do to stop gentrification? Require all sales be run though some sort of "community commission" to see if the buyer "qualified" and would not change the demographic mix of the area? I hope the absurdity of that is self-evident. One can argue that gentrification should trigger more subsidy for poor people. Well more subsidy for poor people may well be a good idea. But the free-market sale of a house is a transfer of monet from (presumably) a richer person to a poorer one. So who is the loser? How would you prevent a (presumably, let's posit) poorer and blacker person from selling to a (presumably) richer and whiter person? Would anyone dare? It seems to me gentrification, if it is indeed a problem, is not one with any apparent solution. Unless one intends society to remain fixed in some current configuration, I see no plasuible solutions.
Note: Don't miss the comments on Morrone's post at 2Blowhards; there are some very thoughtful ones, and I don't mean my own.
In my early days -- late 1970s -- I was on Task Force set up the City of Seattle to stop "red-lining": the practice of not lending to people in poorer, usually black areas od a city. From what I can tell, that practice is pretty-much long gone, especially in a city like Seattle. And that's good. It would be bitter irony if in any way, in any city, anti-gentrification became the rationale for a new kind of red-lining to restrict new investment by "outsiders."