I guess in this hypothetical, imagine all ownership of the rental units suddenly transferred to the tenant. Would the net effect to the economy be positive or negative?
The construction industry would collapse as buying confidence would disappear. Buildings with large amounts of renters would likely fall into disarray over the long term.
Co-ops that are involved in building apartments? They're so few they're irrelevant. It still needs the members to put in a fair amount of money - likely a lot more than the average renter can afford. And it requires "decent" members.
Try being a landlord for the "median" renter, and you'll see how many irresponsible people are out there. A lot of below median folks have zero interest in maintaining their place - even if they own it. They'd make for very poor co-op members.
Seems like the same problem results: now what if you're a new renter? You can't live anywhere, because there's no landlords. Does somebody just give you a house, in this scenario, and if so, who?
I mean, you'd eliminate the rental market entirely, meaning that the only way to live anywhere is to buy.
That would be utterly disastrous. Homelessness would skyrocket. I mean, where are people who can't afford a down payment going to live?
Also, a lot of people don't want to buy, even if they can. If you know you're going to live in a city for a two-year employment contract before moving again, you want to rent.