This persistent strain of bad faith engagement with supply side arguments is baffling, as if every academic paper published in the past decades showing importance of more housing is just the rich hoping for a come up.
More market-rate supply isn't enough—it likely won't bring down rents for poor even if median rents drop; the Urban Displacement Project pointed this out a while ago (though counterfactual is what rents for poor would've been in absence of such housing). urbandisplacement.org/research 
We need billions in social housing that'll directly counter displacement & lower rents for the poor, but at $750K per unit, San Francisco will become Palo Alto before the state can entirely build the housing we need on its own. sfchronicle.com/bayarea/articl…
San Francisco's chief economist said we'd need 100K units to have "significant increase in affordability" equal to giving all low-income San Franciscans $75K housing assistance. At $750K per unit, that's $75 billion in public funds. archives.sfexaminer.com/sanfrancisco/l…
Eric Fischer has a linear model where a "1% increase in the housing stock means a 1.7% decrease in rent" & says you'd need 200K units to bring rents down by two-thirds. At $750K per unit, that's $150 billion in public funds. experimental-geography.blogspot.com/2016/05/employ…
The UCLA Anderson Forecast found a 20% increase in housing stock in California would lead to a 10% reduction in prices. Applied to San Francisco, that's 78.4K units. At $750K per unit, that's $58.8 billion in public funds. sfgate.com/news/article/S…
The Budget & Legislative Analyst said we'd have needed to build 400K units between 1980-2010 to bring prices in line w/national growth rates. If we did 400K for the next 30 years at $750K per unit, that's $300 billion in public funds—$10 billion a year. sfbos.org/sites/default/…
These are all different definitions of what "success" might look like, some more ambitious than others. They all cost a shit ton of money, & I don't think anyone can be intellectually honest & say we could get this money from the federal, state, or city government any time soon.
The truth is that supply-focused groups look at our home supply, costs per unit, & public spending trends & don't see how the state can do what's needed on its own. It's easy to say this is just a ploy to get cheaper units for the rich; it's also lazy & boring.
We're going to need a lot of private housing. We're gonna have to be careful as hell where it goes, we're gonna need strong tenant protections (rent control), we're gonna need to tax & build social housing, but we're also going to need a fucking lot of private housing.
(Aside: @sammymoss425 points out often that per-unit costs for affordable aren't really fair b/c those projects have other spaces (daycare, nonprofit, etc.) that bring up overall costs. But even at half per-unit costs above, it'd be billions I don't see us getting for decades.)
