Why Building a Lot of 'Affordable' Housing Is Bad News for Affordability
Cities become affordable when lots of new housing is built, not when a larger percentage of a small amount of new housing is made "affordable" by regulation.

Happy Tuesday and Happy New Year! With the cost of housing ever-present in the public consciousness, state legislatures reconvening, and elections out of the way, we can expect 2025 to be action-packed with lots of wonky housing policy fights. Rent Free will be here to cover them all.
As policymakers go about considering reforms aimed at making their cities more affordable, it's important to understand what success will look like. Even more importantly, it's important to understand what success does not look like.
To that end, this week's newsletter takes on the mistaken idea that building a high share of below-market "affordable" housing is a sign that a city is becoming more affordable.
If a Lot of New Housing in Your City Is 'Affordable,' Something Is Off
On New Year's Eve, the Boston city government issued a press release touting the good work of its newly reorganized Planning Department at approving new development. The city reports that 3,575 net residential units were approved in 2024, of which a little over a third were "income-restricted."
That top-line number is not necessarily anything to brag about. Despite having some of the highest home prices and rents in the country, Boston is permitting fewer homes than less-expensive peer cities with equivalent populations.
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Similarly sized cities like Washington, D.C., are building more housing than Boston. Atlanta is building way more housing than Boston.
Even more concerning than Boston not permitting a lot of new homes is how many of the homes it is permitting are "income-restricted."
Those are units (often also just called "affordable," "below-market," or "deed-restricted" units) that are reserved for lower-income residents and where rents are capped at steeply discounted below-market rates. Despite the city's celebratory touting of that figure, such a high share of new housing being income-restricted housing is very bad news.
That data point suggests that not only is Boston not building a lot of housing, but that it's vastly under-building what the market demands. It says most of the projects getting approved in Boston are either dependent on public subsidies or command such high rents that they can bear the cost of the city's punishing affordable housing mandates.
Understanding exactly why cities don't become affordable by raising the "affordable" share of the tiny amount of housing that they do build is crucial for getting housing policy right in the new year.
Filtering Up, Filtering Down
In a free market without subsidies and price controls, there wouldn't be such a thing as "income-restricted" units. All housing would be rented or sold at market rates for a profit (save for whatever housing is provided by charitable nonprofits and religious groups).
New housing would be pricey under such a system. But without zoning or other artificial caps on production, housing would still generally be affordable thanks to filtering.
Filtering is the process by which high-income people move into pricey, newly built units, lowering demand (and prices) for the older units they leave behind. Those units are then snapped up by lower-income people, who themselves leave behind an older, less-expensive unit to be taken by even lower-income people.
Studies that follow the filtering process down the income ladder find that the addition of new market-rate units kicks off a chain of moves that ends up leaving more units available in the most affordable neighborhoods.
Boston, of course, does not have a free market in housing. The city's zoning laws artificially restrict how much new housing can be built in the city. One measure of regulatory burden finds Boston has the strictest land use rules in the country.
A consequence of such strict regulations is that the natural market filtering process is thrown in reverse.
Absent new housing coming online at high enough rates to meet growing demand, high-income people stay put in their old units for want of better options. Units become more expensive over time, not less. Lower-income people economize by moving into older, worse housing instead of newer, better housing. People at the bottom rung of the income ladder either move out of town or move onto the street.
(If you want a more thorough explanation, see this piece I wrote about the housing economics of Taylor Swift concerts.)
Just One More Regulation
When filtering has broken down in a city, the obvious move for policymakers is to get rid of the zoning rules, permitting requirements, impact fees, taxes, mandates, and more that stymie new housing production.
Instead, cities like Boston have decided to fix the ill consequences of overregulation with more regulation.
Operating under the assumption that sky-high housing prices are just a force of nature (and not the product of overregulation), Boston created an "inclusionary zoning" policy back in the late 1990s.
That policy requires developers seeking waivers from zoning regulations to include below-market "income-restricted" units in their projects if they are building more than 10 units at a time.
Since Boston's zoning regulations are so restrictive, a high percentage of developers need to ask for zoning waivers to make their projects possible. A high percentage of newly constructed units in the city are "income-restricted" as a result.
Add in the affordable units that are built through federal, state, and locally subsidized housing programs and you end up with a third of new units being "income-restricted."
The city touts those affordable units as a policy success, when in fact they're plain and obvious proof of how overly burdensome the city's zoning regulations are.
If routine homebuilding requires waivers from the laws on the books, then the laws on the books by definition are killing routine homebuilding.
Even if Boston grants every waiver a developer requests in exchange for them building "income-restricted" units, the city is still costing itself new housing.
The voluminous research on inclusionary zoning policies finds that they're an effective tax on new housing that lowers housing production and raises housing prices.
For-profit builders need to make a higher rate of return on their market-rate units in order to make up for the tax imposed by "income-restricted" units. If the returns on market-rate units in a project don't cover the costs of the inclusionary zoning tax, then that project just doesn't get proposed at all.
That means that in Boston, fewer units overall get built and the market-rate units that do make sense to build are incredibly expensive.
Bad to Worse
Things are going from bad to worse in Boston. In October 2024, updates to the city's inclusionary zoning policy went into effect.
The pre-October regulations required that the builders of 10 units or more who received zoning relief make 13 percent of their new units income-restricted. The new policy requires all projects of seven or more units to be at least 17 percent income-restricted. They must also be restricted to incomes of at most 70 percent of the area median income.
This makes Boston's inclusionary zoning policy one of the most burdensome in the nation. One should expect the share of "income-restricted" units to rise as a percentage of new development going forward in Boston. The city will surely issue celebratory press releases when that happens, saying that their new policies are working. In the background, the overall number of homes will be falling.
As yet another example of more bad news presented as good, the city has launched a Housing Accelerator Fund to subsidize projects that are already approved and permitted but haven't started construction because of financial difficulties.
If a developer can't attract financing for already-approved housing in a high-priced, undersupplied city, something has gone very wrong indeed.
A Tale of Two Cities
In 2005, the Texas Legislature, responding to the concerns of Austin homebuilders, banned mandatory inclusionary zoning in the state. From that year on, Texas cities were prohibited from conditioning the approval of new, code-conforming housing on the inclusion of "income-restricted" units.
Affordable housing advocates opposed Texas' inclusionary zoning ban at the time and have continued to argue for its repeal on the grounds that inclusionary zoning is a powerful tool for creating affordability.
Yet 20 years later, it's Texas' megabuilding, inclusionary zoning–free cities that are relatively affordable and affordability-mandating jurisdictions like Boston that aren't.
According to the most recent rental data from Apartment List, median rents in Austin are $1,394 a month and have fallen 7.2 percent year-over-year. In Boston, median rents are holding steady at $2,298.
Boston might be the worst offender when it comes to bragging about how its policies are making things worse. But the policy preference for shrinking the amount of housing that's built in favor of boosting the percentage of housing that's "affordable" is a nationwide phenomenon.
California's state planning system is predicated on the idea that localities should mostly be building income-restricted housing. When they don't, politicians complain that they're overbuilding market-rate housing and call for greater subsidies and regulation.
Several states are now copying California's planning approach.
The Biden administration doled out new zoning reform grants, initially intended as an incentive for cities to repeal regulations on new housing, to cities that adopted inclusionary zoning policies.
In the past decade or so, a wave of inclusionary zoning requirements have been passed in Portland, New York City, Seattle, Pittsburgh, and more. Some of these are worse than others. All these policies implicitly accept the idea that we should sacrifice more housing for some additional "affordable" housing.
In states where inclusionary zoning is the norm, the policy hamstrings otherwise productive zoning reforms.
Bills that "upzone" land so that more units can be built are too often larded down with inclusionary zoning mandates requiring some (or all) of the newly legal units to be "income-restricted."
In effect, more housing is exchanged for less housing. Peter is robbed to pay Paul. The bad tradeoff of lower overall housing production for a higher share of "affordable housing" is extended into the future.
Aside from Texas, a handful of states have banned inclusionary zoning policies. More states should follow suit.
Housing becomes affordable when a lot of it is built, not when capital-A "affordable housing" makes up a larger slice of a tiny new housing pie.
Quick Links
- The Wall Street Journal profiles the mixed-use Costco/apartment building development happening in Los Angeles that's made possible by recent state zoning reforms that allow streamlined approval of some residential projects in commercial zones. No longer are suburban big-box retail and urban walkability in conflict.
Costco is building apartments above its stores to address the affordable housing crisis, starting early this year.
Walking downstairs and getting a $1.50 hot dog gives new meaning to "affordable walkability."
It includes free membership, a rooftop pool, fitness area, gardens/… pic.twitter.com/28eBI4ORk2
— Andrew Lokenauth | TheFinanceNewsletter.com (@FluentInFinance) January 4, 2025
- Developers in Utica, New York, are asking the U.S. Supreme Court to take up their challenge to the city's seizure of their property. If the court does take up the case, it would give it the opportunity to overturn the infamous 2005 Kelo precedent that removed guardrails against eminent domain abuse, writes Reason's Jacob Sullum.
- Delaware's governor-elect is saying the right things about housing affordability while proposing some pretty modest state-level zoning reforms.
- Berkeley, California, has created an amnesty program whereby people can legalize their illegally built accessory dwelling unit (ADU). A recent study looking at San Jose, California, found that most ADUs are built without permits.
- In California, an anti-LED light group sues over a plan to install a light display on the Bay Bridge in San Francisco, reports The San Francisco Standard. The suit claims the installation, far from being a beautiful addition to the city, will be "eye candy for a few private individuals who wish to use the public San Francisco Bay Bridge as their own personal playground." The anti-LED group is suing under the same environmental law that anti-development activists use to challenge the approval of tens of housing units a year.
- Even as New York City tries to goose housing production with liberalizing zoning reforms, the city's rent stabilization law is forcing more and more units off the market.
- Meanwhile, more cities in New York are taking the opportunity created by the state's new "Good Cause eviction" law to pass rent control policies of their own. Maybe supply and demand works differently in Rochester?
- A Maryland man is in hot water for building a go-cart track on his property without the proper permits. What's next, a permit to toast toast in your own damn toaster?
- Camping bans are proliferating in the wake of the Supreme Court's Grants Pass decision, which lets cities ticket people for sleeping in public even if there are no available shelter beds. Last week, Rent Free reported on how unsheltered homelessness in the United States continues to climb to record levels.
- Despite some last-minute legal maneuvers from New Jersey, New York's new congestion tolls went into effect on January 5.
Rent Free is a weekly newsletter from Christian Britschgi on urbanism and the fight for less regulation, more housing, more property rights, and more freedom in America's cities.
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If a subsidy is required to live there, it's not affordable by definition.
""Despite some last-minute legal maneuvers from New Jersey, New York's new congestion tolls went into effect on January 5.""
So how long until the MTA starts crying broke again?
So, the congrestion problem vanished?
Not a chance.
Fastest express bus trip from the Bronx to lower Manhattan since last summer. That is only one data point but it is a good one.
Why it's like a repeat of Commie-Healthcare.
It's sooooo 'affordable' nobody but 'Gun' THEFT criminals can afford it anymore.
Well, Christian is largely correct here. Older housing becomes more affordable when builders are allowed to build or renovate newer, more desirable units. The less desirable, older stuff becomes less in demand, and doesn't command as high a price.
No he's not. Filtering isn't relevant when buys/sales are driven by tax advantages rather than actual housing. And US real estate has been a tax driven market ever since mortgage debt was created and became a form of tax advantaged financing.
Further, what happens in brownfield development with tax advantages is that new development REDUCES supply. That's how gentrification works. That reduced supply forces occupants without the tax opportunity to compete with others for FEWER units. Since those are also lower rungs on the ladder, they get pushed out of housing altogether like musical chairs.
Greenfield development adds supply - but over the decades, that just gets further from where those people want to live. This requiring them to add to transportation expenses and at a certain point, the distance is an entirely different city and transport no longer matters
"No he's not. Filtering isn't relevant when buys/sales are driven by tax advantages rather than actual housing. And US real estate has been a tax driven market ever since mortgage debt was created and became a form of tax advantaged financing."
JFucked continues to lie about finances; he is a dumb shit, ain't he?
Oooo, there people go in this thread again confusing me with terminology. I thought "brownfields" were contaminated lands.
I meant just previously developed for the same purpose it is being redeveloped for. Not polluted or toxic or even devalued via blight or 'urban renewal'.
Maybe there's a different word but that process of gentrification covers it. Where eg a 20 unit four story apt building of studios and 1br is turned into 8 luxury condos. That's a reduction in supply.
Nonsense on brownfield development.
First of all, I have never seen or heard of a place in the US where housing is not "affordable". If so, thousands of homes, condos, and apartments would sit empty.
Second, what you seem to want is cheap housing, i.e. places with prices and rents that people with lower tier incomes can afford. Just a reminder, then, that this equation has two sides: one with housing cost and one with income. So if you want teachers and firefighters and even baristas to afford market housing in some places, you can push to pay them more. Of course, that also has consequences.
Third, even with a perfect free market, there are no magic solutions. In expensive areas, housing will always cost more. And the market solutions there, to meet a lower price point, will be unappealing. Stop deluding yourself and others that we can find a free lunch solution to housing.
As far as I am concerned, teachers (in New Jersey at least) should be paid minimum wage, because they don't even have to know how to read or write!
I’m convinced the drones flying over NJ are tax collectors looking for illegal ADUs:-)
"The market solutions there, to meet a lower price point, will be unappealing"
Appealing enough for Democrats on the NY City Council to approve a citywide upzoning. But unappealing for Republicans on the City Council -- every one of them opposed it.
In the interest of journalism, you should stop describing tax-payer subsidized housing as "affordable".
This article assumes the market will attain affordable housing if left alone. It won't. Even the Austin example is flawed, as evidenced by the "more affordable than Boston" actual numbers which show even average Austin rents out of reach for many. The only ways we get affordable housing are for the government to build, own or lease, and operate it using revenue bonds for construction financing; and/or giving away publicly owned land to for-profit or non-profit developers in return for building ONLY affordable housing, perhaps also with revenue bond financing. The market won't work because the profit motive precludes acceptable investment returns on affordable renral and sale housing. We could possibly perform tax code surgery to address some of this problem, but that skews the market model as much as the government providing housing directly, which we know gets results.
"...The only ways we get affordable housing are for the government to build, own or lease, and operate it using revenue bonds for construction financing; and/or giving away publicly owned land to for-profit or non-profit developers in return for building ONLY affordable housing, perhaps also with revenue bond financing..."
This lefty shit has never read anything regarding government-provided housing.
He is a stupid shit, ain't he?
No city in the past century has even tried a free market approach. Even NYC's recent huge upzoning doesn't go far enough -- and it met with unanimous disapproval from Republicans.
"...For-profit builders need to make a higher rate of return on their market-rate units in order to make up for the tax imposed by "income-restricted" units..."
Yes, that BMR unit just occupied by the slaker just raised the market price of all market rate units.
It’s about time you write about the root of what is going on in the blue cities /states. I’ve always called it reverse rent control, instead of investors taking the hit, the taxpayers or market rate units are and will.
Next up write about property taxes and the carried over costs to housing/rental building and prices.
Owners of market rate housing in NYC have experienced a tremendous windfall as prices have risen.
The solution is to work to build up distressed towns in decline, not shove ever-more housing into a tiny area and make yet another urbanized craphole. Dense areas SUCK and are full of crime, misery, and mental illness. It might be nice for the corporate labor pool, but they're all a bunch of subsidized, censurious government DEI agents anyway, so frankly, screw them.
I bought a house with the idea that the neighborhood would stay the same, not become packed with dense, cramped housing.
Also most of the "affordable" housing is a laughable joke which would eat up 40-50% of take-home pay around here, based on the income levels I've seen listed. My household makes 2x-4x that and "affordable" is what WE'RE paying for a full-on mortgage (admittedly, it's a small place, as we didn't want to overbuy... except now a big house to expand into would cost 2-3x what it would have been 10 years ago).
"Dense areas SUCK and are full of crime, misery, and mental illness."
Liar. New York City has one of the lowest homicide rates among large US cities and it has the lowest suicide rate outside of Washington DC.
"I bought a house with the idea that the neighborhood would stay the same, not become packed with dense, cramped housing."
Unless you bought the entire neighborhood you have absolutely zero right to hold that idea. You are a fascist or s communist if you want to deny others their property rights.
I have to keep remembering that "affordable" and "inclusionary" are sometimes terms of art that may be very much at odds with their plain meanings. Like, every so often I read here about "inclusionary zoning" and think, "That's good, it's zoning that allows (includes) more." And "affordable housing" makes me think of housing someone can afford.
New York City just approved a massive change to the zoning laws citywide, reducing regulations, allowing higher densities, and providing for more streamlined approvals. Every Republican on the City Council voted against it. But Republicans have never believed in free markets.
“A government which robs Peter to pay Paul can always depend on the support of Paul.”
— George Bernard Shaw
Can we please stop calling it "affordable housing" and just be honest and call it ghettos?