Comment by cyberax
4 hours ago
> The flophouses and dorms and SROs were a key part of the housing market that kept Manhattan more affordable and therefore livable in the 20th century, when density was up to 40% greater than it is now.
???? Can you provide the citation for higher density in the early 20th century?
> I live here. The thing making Manhattan unlivable is that a one-bedroom is $4500 in the east village due to not enough supply.
And there is never going to be enough supply. Your only choice is to Detroitify your city.
"Just build more" in Manhattan is beyond ridiculous. It's literally the definition of madness: "The definition of insanity is doing the same thing over and over again and expecting a different result".
> Can you provide the citation for higher density in the early 20th century?
It was a quick google search and the value was taken from the Gemini result, which is not great practice. Thank you for asking for citations. Unironically! Good discussion on this site matters to me, and I want my positions to have strong foundations.
I looked into it more deeply and have found the actual numbers. The 1910 density was more like 54% higher.
Manhattan reached its peak population of ~2.3M around 1910, with a built-up area on the island of ~4,000 hectares=15.44 square miles. This gives a population density of 149k people per built-up square mile. This is per NYU professor Angel Shlomo's 2015 paper, which seems to be the most in-depth analysis I could find ([0]). We use built-up area because north Manhattan still had large tracts of uninhabited farmland at the time; this area should be excluded to better represent the experience of the residents.
Manhattan's current population is ~1.66M (per [1]), and I am estimating the current built-up area at 4466 hectares=17.24 square miles, as this was the exact built-up area given in [0] for 2013. I am assuming Manhattan was, then and now, basically fully built-up and therefore the area is unchanged. (If I'm wrong, then I would guess there's actually more built-up area now, and therefore the population density is lower, strengthening my POV.)
This gives a current Manhattan population density of 96.3k residents per built square mile. This means the peak density in 1910 was actually (149k/96.3k=)154.7% what it is today! My initial Google estimate was undershooting it.
Ergo Manhattan today is nowhere near its historic density.
From all this, I think it is clear that Manhattan and NYC are nowhere near their carrying capacity. There are other safe, clean metros on planet earth with much higher density and lower housing costs (e.g. Seoul), and the thing preventing greater density and lower costs isn't some fundamental upper bound or even economic incentives: it's just zoning.
What has changed since 1910? New York City has much better infrastructure that would allow even greater density in the city, outer boroughs, and surrounding area without negatively impacting quality of life. Modern building techniques allow us to build far more than six stories high without imperiling residents in tenement housing. There is a robust subway and rail network that allows commuters to come from other, even less dense areas. I think we could build to these historic densities much more safely and pleasantly now, which is also the opinion of the authors of [0].
> And there is never going to be enough supply.
I simply do not understand your rationale. We have not seriously tried to provide enough supply, due to the zoning constraints.
In 2023 there were ~3.7M housing units in NYC ([2]). We are adding ~9,450 units every quarter ([3]), for a total of ~38k units per year, a yearly increase of about 1%. This is a drastic undershooting of NYC's own goal to build 500,000 new homes from 2022 to 2032, which would look more like 13k to 14k new units per quarter ([3])—and some groups estimate that the housing shortage is even more than that 500k units. It takes 3.4 years on average to build a unit in NYC and more than four years to build an apartment in Manhattan ([3]), which is absurdly slow, and the vacancy rate is an absurdly low 1.4% where ~5% is the marker for a healthy real estate market ([2]+general knowledge).
Manhattan (and NYC in general) has onerous zoning and review requirements that prevent the adequate building of new housing to meet demand. Of the existing building stock, fully 40% of it would not be permitted nowadays, primarily because they are "too tall" or "have too many apartments," "too many businesses," or any number of other absurd requirements in a city with extremely high housing costs ([4]). There are even regulations around having enough parking spots in parts of Manhattan, a place with ample public transit, lots of street parking, and subsidized van service for the disabled. These buildings are the backbone of our urban core; they provide housing for hundreds of thousands of people and commercial space that drives much of the NYC metro area's economy, the GDP of which is over $2T and makes up ~9% of the US economy ([5]).
Conversely, there are many land uses in Manhattan that fit these zoning requirements and are ridiculous and uneconomical uses of land. For example: a small parking lot structure in the West Village (of which there are a depressing number) is a valid usage of land, while an eight-floor apartment building with an elevator and retail space on the bottom is "too tall" and disallowed because it would exceed the 80-foot limit in the village. How does another small parking lot serve a city gripped by housing crisis that is caused by a shortage of units—which also has excellent rail connection and plenty of parking already—better than an apartment building? The apartment building could even be on top of a parking garage if we wanted it to, but adding the residential space and/or more commercial space (which raises incomes via agglomeration and therefore improves affordability by higher salaries relative to housing) is not allowed because it runs afoul of height restrictions.
This is irrational policy that directly contributes to the housing crisis.
> Your only choice is to Detroitify your city.
It's interesting that you claim densifying Manhattan will turn it into Detroit.
I claim that Detroit was hollowed out precisely by anti-density and pro-suburbanization practices. I'm lazy and have been typing forever at this point, so: https://en.wikipedia.org/wiki/Decline_of_Detroit#Population_....
When you send factories to the suburbs and then put highways straight through the neighborhoods in your city where people actually live and work, that's not densification leading to bad outcomes. It is detonating a city via discriminatory urban policy and then falsely claiming it is the natural end result for those pesky cities and their residents.
[0] https://marroninstitute.nyu.edu/uploads/content/Manhattan_De...
[1] https://censusreporter.org/profiles/06000US3606144919-manhat...
[2] https://www.nyc.gov/content/tenantprotection/pages/fast-fact...
[3] https://www.nytimes.com/2025/12/23/nyregion/nyc-housing-deve...
[4] https://www.nytimes.com/interactive/2016/05/19/upshot/forty-...
[5] https://edc.nyc/sites/default/files/2025-12/NYCEDC-2025-Stat...
(This is a more readable but much less detailed intro to [0]: https://urbanomnibus.net/2014/10/the-rise-and-fall-of-manhat...).