[HN Gopher] Just Put It on a Map
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Just Put It on a Map
Author : surprisetalk
Score : 131 points
Date : 2026-03-16 10:53 UTC (4 days ago)
(HTM) web link (progressandpoverty.substack.com)
(TXT) w3m dump (progressandpoverty.substack.com)
| ancillary wrote:
| Is "land value" the right term here? The NYC example uses
| assessed property value, which I think is a function of both the
| land under a property and the building itself. In that case,
| these "taller means more valuable" graphics are at least
| partially reflecting the fact that a tall building is probably
| more valuable than the short one next to it?
| svcphr wrote:
| Land and "improvements" are assessed separately, and I believe
| this is plotting just the assessed land values. In the small
| text about each map, it says to use the settings to switch to
| full assessed value or improvements. But still, it's very hard
| to actually assess land value in an area like Manhattan where
| there are basically no land-only transactions
| francisofascii wrote:
| It is a good question. The author seems to use the field
| "assr_land_value", and there is also an "assr_impr_value". So
| it very well may be correct.
| xnx wrote:
| Probably fun to make but harder to read compared to a bar chart.
| flir wrote:
| I suspect the visualisation is hiding a power law distribution
| that would be much more apparent in 2d.
| the_sleaze_ wrote:
| > Show an elected official
|
| What is the problem this visualization seeks to make obvious? Is
| it just neat to think about and make?
| larsiusprime wrote:
| Author here. This is the problem we are seeking to solve, we
| are property tax reform activists:
|
| https://open.substack.com/pub/progressandpoverty/p/enacting-...
| PeterHolzwarth wrote:
| A minor thing - I know that article is part of a broader body
| of work and is not meant to solely present your ideas by
| itself. But nonetheless, since you linked to it, I had to
| scan down quite a bit to answer the question that was
| immediately on my mind: "tax reform for what purpose and
| why?"
|
| And, an aside, I'd personally recommend getting rid of the
| emoji bullet-point additions: in this day and age, well, you
| know.
| larsiusprime wrote:
| Good points! Thanks.
| korkoros wrote:
| The overall claim is true - yes put it on a map.
|
| But I'm not a fan of these particular maps because the use of 3d
| makes them harder to read. The isometric view and rotation away
| from north at the top break conventions that people use to orient
| themselves in the map and connect it to their lived experiences
| on the ground. I'm reasonably familiar with NYC geography, and I
| could not immediately recognize the landscape I was looking at in
| these maps. Ironically, it was only because I already knew the
| answer to the question that I could do so: "oh that huge green
| spike must be Manhattan".
|
| I think a 2d choropleth map with a diverging color scale centered
| on the mean value would work better.
| larsiusprime wrote:
| The main purpose of the 3D is to communicate the extreme
| differences in scale of value, which chloropleth alone doesn't
| always get across as it flattens the magnitude disparity.
| Keeping true north to avoid confusion is a good point.
| jeffbee wrote:
| Yeah, I agree. And if the surface is complex the Z features
| tend to obscure the complexity. I make maps like these for the
| cities of Berkeley and Oakland, but I use a color scale. And I
| usually aggregate at a larger granule than parcels. For e.g.
| https://observablehq.com/@jwb/2024-25-berkeley-property-tax-...
| paulirish wrote:
| +1. Also, I had to go look at their interactive viewer because
| that color scheme choice (dark purple = low, light green =
| high) seemed 100% bonkers. It's the legit "plasma" scheme, but
| based on my limited experience with colorbrewer schemes, I was
| confused.
| svcphr wrote:
| > "1. People have wildly incorrect intuitions about where land
| value is concentrated"
|
| Fwiw this sort of land value gradient has been studied in
| economics for ages. See papers on monocentric city model, going
| back to Alonso (1964), Muth (1969), and Mills (1967). Or even
| further back, von Thunen was talking back in 1826 about how land
| values spike as you get closer to the marketplace.
| PopAlongKid wrote:
| I was waiting to read about what these "wildly incorrect
| intuitions" were, but it's never explained. The maps correctly
| matched my own intuitions.
| larsiusprime wrote:
| Author here. Our blog generally concerns property tax reform
| for our regular readership which is admittedly less clear to
| a new reader coming in cold: the intuitions I'm referring to
| is the average homeowner kind of assumes any tax reform (such
| as shifting taxes off buildings and onto land) is designed to
| impoverish them personally. The purpose of these maps is to
| show such people where land value in cities is really
| concentrated - Ie, not the m the suburbs. Mono centric city
| value might be intuitive to academics, but it's not among
| regular everyday people.
| esrauch wrote:
| Do you mean people underestimate how steep the gradient is,
| or they don't know it at all?
|
| It seems kind of dubious to me that "everyday" people don't
| understand that land in cities is worth more than land in
| suburbs. It seems very transparent that you get a smaller
| lot size for the same price.
| larsiusprime wrote:
| Both. They do understand that it's worth "more" in the
| city but they vastly underestimate the magnitude, and
| they vastly underestimate what that means in terms of
| where the total bulk of land value is concentrated, and
| therefore what the distribution of winners and losers
| will be in any tax shift scenario.
| JoelMcCracken wrote:
| This is generally a big problem in Pittsburgh where huge
| areas of the most valuable land is owned by "nonprofits"
| the_mitsuhiko wrote:
| > I was waiting to read about what these "wildly incorrect
| intuitions" were, but it's never explained. The maps
| correctly matched my own intuitions.
|
| If you are into land value tax discourse maybe, but from my
| experience at least there is a big lack of awareness of the
| impact of economic activities on land values as they are not
| reflected by anything that people get in contact with. That's
| especially true because neither rents nor property taxes (the
| one thing people might have exposure to) fully capture it.
| skyberrys wrote:
| I had guessed land in Manhattan vs the bronx as 7x more
| valuable, based on living in the Bronx and paying rent. For
| the joys of living in the Bronx my rent was under $1k and I
| had a separate bathroom that was part of my studio
| apartment. Meanwhile Manhattan apartments wanted $2k and I
| had to use a bathroom shared with the floor.
| dmd wrote:
| Same. My assumption, before seeing this, was "ok, I'm going
| to guess land in a city is worth 100 or 1000x land anywhere
| else", and I guess I overestimated a bit.
| AlfredBarnes wrote:
| Was cool to see a few of the cities, and then cross reference
| with some searches on pricing to get a better understanding of
| the actual cost.
| paulluuk wrote:
| This is great, and it also feels like a great way to answer the
| question "Where should I buy a house if I want to be close to the
| center but not in the expensive area?".
|
| > Let's play a guessing game. How much more valuable is land in
| Manhattan than in the Bronx? Take a guess, then scroll down for
| the answer.
|
| As someone who has never been in New York and doesn't live in the
| US, I knew beforehand that I would fail this test very hard,
| haha.
| ndriscoll wrote:
| Manhattan is where basically everything you might associate
| with New York is (Empire State building, World Trade Center,
| Times Square, Central Park, etc.). The Bronx is where Jennifer
| Lopez reminds us that she came from as she keeps it real.
| Drunk_Engineer wrote:
| Nice idea, except the actual mapper site requires a google login
| to view.
| larsiusprime wrote:
| Author here: it's a cheap rate limiter and something we are
| looking to remove soon.
| jonathanberger wrote:
| Note that the site that generated these does not support any San
| Francisco Bay Area cities. I learned this only after being forced
| to "Sign in with Google".
| VintageCool wrote:
| It says in the linked article that they only have support for 9
| cities so far, and they list them as:
|
| Spokane, WA
|
| Syracuse, NY
|
| South Bend, IN
|
| Bellingham, WA
|
| Morgantown, WV
|
| Cincinnati, OH
|
| St Paul, MN
|
| Rochester, NY
|
| New York City, NY
|
| It also says that they are working on improving the data
| pipeline so that they can reduce the amount of time it takes to
| add new cities to their dataset and visualization.
| etiennebausson wrote:
| How much the land is worth is only one of the parameters.
|
| Notoriously, the maintenance cost for suburbs and their
| infrastructure is significantly lower than the tax they bring.
| Shouldn't that be a major point un tax decisions?
| JoelMcCracken wrote:
| IIUC the maintenance costs of suburbs is _higher_. Not sure if
| you meant that.
| bombcar wrote:
| I've seen it argued both ways and I've yet to see real
| evidence, especially considering many suburbs are themselves
| actually cities/towns, and that cities seem to fight tooth-
| and-nail to prevent suburbs from leaving.
| ghaff wrote:
| Yes. And it's not like you can tear up all the roads
| leading out of a large city (or just let them decay).
| jeffbee wrote:
| Have you ... looked for evidence? I guess I always felt
| that it was self-evident that horizontal development costs
| way more in terms of roads, pipes, and wires, and at the
| same time raises almost nothing in terms of revenues.
| Residential-only development patterns never pay their own
| way. https://resources.environment.yale.edu/kotchen/pubs/CO
| CS.pdf
| bombcar wrote:
| I've looked a few times, and it quickly (at least to me)
| appeared to depend on what you bucket and where you can
| torture the data and make it confess.
|
| Single buildings can cost as much as my entire "city" -
| one World Trade Center _alone_ cost $4 billion.
|
| An example of how you can bucket things is do you look at
| property tax, income tax (and if you do, is it where the
| "nexus of generation" is done, where the worker lives,
| where he works, where she's headquartered, etc). Around
| here basically _none_ of what we would call "support" is
| paid for by property tax except schools (95% or so) and
| sewer (which is billed as a property "tax" though it's
| actually per connection/size).
| jeffbee wrote:
| That's exactly the point. On big vertical building covers
| 1 acre of land but it has 80 acres of interior space.
| There's one honking water pipe in the basement that will
| never need to be replaced, instead of mile after mile of
| water pipes with leaky fittings every 50 feet.
| bombcar wrote:
| $3.9 billion pays for a lot of leaky pipes - and the pipe
| has to source water from _somewhere_ - https://en.wikiped
| ia.org/wiki/New_York_City_water_supply_sys...
| ghaff wrote:
| In my town schools aren't 95% of property taxes but they
| are the majority. Add emergency services, water (though
| that's a separate bill), same for electricity. Less
| familiar with road and bridge maintenance. Assume some
| comes from the state and feds but at least some is local.
| bombcar wrote:
| It's the part that flows through the feds that lets you
| get whatever answer you want - is a local bridge being
| 80% federal and state-funded the cities supporting the
| town? Or is that less than the income tax taken from the
| local town?
| ghaff wrote:
| I agree and you'd have to do a lot of study and the
| answer is still probably it depends. Presumably nuking
| some distressed Midwest cities isn't the answer, and a
| lot of these cities are somewhat spread out. But it's
| hard to argue with they're not bringing in tax revenue
| because in aggregate they're pretty poor. Some luxury
| high rises to replace some of the many single-family
| homes is not going to help Detroit absent a big influx of
| jobs.
| Night_Thastus wrote:
| You have it backwards. Suburb infrastructure is expensive and
| the land pulls in little tax money by comparison. They're
| almost always a net loss on the city's budget.
| Night_Thastus wrote:
| The other thing people often forget is that the 'land value' is
| also a measure of the city's well-being.
|
| Those big spikes you see in the center? They cost _very_ little
| for the city to maintain, and generate oodles of tax money.
|
| Those big, wide areas out towards the fringes? They generate next
| to no tax income and cost a _lot_ to maintain.
|
| The urban subsidizes the sub-urban. The sub-urban lifestyle would
| be completely impossible without the ultra-dense urban centers.
| If planners and citizens don't keep that in mind, you can easily
| end up with an insolvent city budget that is bleeding from
| maintaining all the utilities and roads stretching out to the
| exterior.
| ghaff wrote:
| The Bronx is sub-urban? As someone else noted, Manhattan and
| The Bronx are totally different in ways that probably has
| little to do with population differently.
| api wrote:
| Utilities and roads out into the suburban may be underpriced,
| but there's a dark side to cities too. The suburbs and rural
| areas are often where people can afford homes.
|
| I've had this hypotheses for a long time that the car is, at
| least economically, only incidentally about mobility. In
| reality it's a tool for obtaining leverage in the real estate
| market.
|
| Without sprawl urban landlords would have a captive audience
| and would extract all surplus. See: the law of rent.
|
| I have a related hypothesis that the car drove the mid century
| middle class explosion in the US and some other countries, not
| by providing car jobs or any of the other conventional
| mechanisms but by allowing people to escape the law of rent.
|
| Telework does this today for those who can use it, allowing
| people to leave high cost cities where good jobs are
| concentrated. The car did that until we reached the scaling
| limits of sprawl.
|
| Also why I am a huge fan of Georgist taxation. Unfortunately we
| are moving in the opposite direction, taxing productivity and
| investment and wealth instead of taxing land and rent.
| jeffbee wrote:
| Yeah well the problem is that after a moderately prosperous
| person buys a car and a house out in the suburb, the act of
| having spent half a million dollars makes them believe that
| they are entitled to drive their car into the city and enjoy
| the commerce and culture that the city fosters, plus free
| parking and toll-free roads and subsidized gas. None of those
| are great! In my town this manifests as people who live just
| over the county line in unincorporated places who
| nevertheless feel entitled to participate in city
| deliberations over road design and parking policies.
| munchler wrote:
| Most true suburbs aren't within the big city limits, so I'm not
| sure your point is well-founded. For example, in the DC area,
| the suburbs aren't even in the same state as the city and yet
| the suburbs seem to be thriving.
| umanwizard wrote:
| DC is an exception, most American cities have large swaths of
| suburbia within the city limits and even larger ones within
| the same state.
| socalgal2 wrote:
| Those suburbs outside the city limits still need money. They
| get it from state and federal funds which were mostly
| collected from people in the city limits. For example the
| Highway Trust Fund as one of many examples. If you check the
| per capita spending, it's higher for suburbanites than
| urbanites but the urbanites are putting in more money.
| bpt3 wrote:
| Absolutely not in the case of the DC metro area, on both
| the MD and VA sides. Those counties subsidize DC proper in
| various ways, along with the less populated portions of
| their own states, and because the median household income
| is so high, they also pay a disproportionate amount of
| federal income taxes when compared to DC residents.
|
| I also have no idea why you think city dwellers are the
| primary contributors per capita to the Highway Trust Fund
| which is funded via a tax on fuel (i.e. miles driven).
| michael1999 wrote:
| The road network expansions and maintenance required to
| support the suburbs does. Ottawa has this exact problem. They
| are widening inner-suburb roads to satisfy demand created by
| outer-suburb development. A double-whammy.
| marcosdumay wrote:
| So, what policy do you change after you learn that economic
| activity always concentrate on a small part of the city? You go
| and outlaw a natural law?
| gzread wrote:
| You aim to build more centers and less outlying regions.
| larsiusprime wrote:
| 1. Stop restricting what can be built, especially in the
| super valuable city centers
|
| 2. Shift taxes off of building (which punishes development)
| and onto the passive holding of land (which discourages idle
| land speculation)
|
| In other words, change man's laws, not nature's.
| cyberax wrote:
| > Those big spikes you see in the center? They cost very little
| for the city to maintain, and generate oodles of tax money.
|
| May I introduce you to the budget for the MTA that is larger
| than the GDP of several countries?
|
| Cities are _expensive_. Especially dense cities like NYC.
|
| > Those big, wide areas out towards the fringes? They generate
| next to no tax income and cost a lot to maintain.
|
| And this is the biggest lie.
|
| These suburbs? They generate most of the wealth in the US
| because the most affluent people live there. Buildings don't
| produce value, _people_ do.
| mmooss wrote:
| > Cities are _expensive_. Especially dense cities like NYC.
|
| But much cheaper per capita than everyone owning a car, an
| acre, traveling long distances for everything, and providing
| infrastructure etc. for all those people. MTA provides 6.5
| million rides per day (!). Imagine that in daily car trips.
|
| https://www.mta.info/document/194491
|
| The difference is that people need to put their money
| together and build shared resources like the subway, and then
| then some think it's more expensive because taxes and
| expenditures are higher. But you don't need a car, gas,
| insurance, etc.; the store is two blocks away; there is much
| more of everything. It works really well and people pay lots
| of extra money to live in much smaller spaces in cities.
| hunterpayne wrote:
| "Those big spikes you see in the center? They cost very little
| for the city to maintain, and generate oodles of tax money."
|
| This is just false. The biggest cost in the suburbs is
| education. In the city cores, education costs exactly the same
| or more (per capita) but police services are the biggest
| expense. You are confusing the expenses of commercial property
| (where nobody lives) with residential property. But people
| still live in those urban cores and the expenses they generate
| are substantial.
| AnthonyMouse wrote:
| This is mostly a result of zoning, isn't it? The high land value
| areas are the ones where you're less prohibited from building
| taller buildings. If the thing people actually want is indoor
| space then the piece of land where you can build a skyscraper is
| worth a lot more than the one which is limited to a single family
| home.
|
| Someone should probably tell the homeowners with a high ratio of
| land to house who like to see their property values increase.
| larsiusprime wrote:
| It's not just zoning, though that exacerbates it. City centers
| are where economic activity tends to be concentrated so even
| without zoning you would see these exponential land value
| effects as you approach the centers of economic activity (and
| indeed, we did see these same relative patterns prior to the
| passing of modern zoning laws).
| AnthonyMouse wrote:
| Weren't transportation and communication a lot slower if you
| go that far back? Zoning laws started getting imposed not
| long after the invention of the telephone and the internal
| combustion engine and before either of them were in the
| possession of the majority of people.
|
| The value of land in an urban area is obviously going to be
| higher than it is in a rural area just as a matter of
| scarcity, but it's not at all obvious that the reason it's
| currently so much more expensive in Manhattan than in the
| places directly adjacent to it isn't primarily a result of
| zoning just because that might not have been the reason in
| 1890.
| larsiusprime wrote:
| If you're talking about the Manhattan effect specifically,
| I'm sure that zoning has a large effect on the extremeness
| of it. If you're talking about "land gets exponentially
| more valuable in the city center", then you see that
| pattern everywhere and indeed we saw it in the historical
| pre-zoning period as well. Agglomeration effects are sticky
| regardless of what time period you're in, what changes is
| the coefficients on the exponential equation.
| AnthonyMouse wrote:
| You keep saying "exponentially" but let's look at the
| median rent for e.g. a 1 bedroom in Manhattan vs. the
| Bronx. It's around twice as much in Manhattan, because
| now you're measuring prices per-unit of indoor space
| rather than per-acre of land.
|
| In a formal sense you can call this exponential. It's
| twice as much in Manhattan as the Bronx and twice as much
| in the Bronx as in some location even further out. But if
| you're trying to explain the >100x difference in the
| price of _land_ between the Bronx and Manhattan, the ~2x
| difference in how much people value living there because
| of agglomeration effects is not the dominant effect.
|
| And you would expect the densest places like Manhattan to
| have the _strongest_ agglomeration effects. You can
| ratchet up permissively zoned land costs through zoning
| just by increasing the level of restrictions elsewhere,
| e.g. ban >2 story buildings instead of banning >5 story
| buildings, but the willingness of people to pay more in
| order to live near things is proportional to the number
| of things they would be paying more to live near.
|
| On top of that, the zoning restrictions exacerbate the
| agglomeration effects. If you could build taller
| buildings in the places you currently can't then the
| premium commanded by housing in a dense area would go
| down by increasing the supply of it.
|
| Suppose you have three neighborhoods. A has 10 story
| buildings and a median rent of $2000, B and C both have 2
| story buildings and a median rent of $1000. You then
| rezone B with the result that new construction happens
| and it now has 5 story buildings. Local housing supply
| just increased by more than 20%. Rents are now $1700 in
| A, $1300 in B and $900 in C, because supply increased and
| some people moved from both A and C to B, which became
| more desirable. People then say "look, you've increased
| rents in B by $300" and blame agglomeration effects and
| try to argue against doing it. But the average rent in
| the city went from ~$1700 to ~$1500 and >20% more people
| now have housing.
| cheriot wrote:
| Now map property taxes per acre and tell me who's subsidizing who
| in this country. Urban3 has been doing the work:
| https://codesigncollaborative.org/urban-revolution-through-d...
|
| Municipal costs per resident are effectively the inverse of these
| maps because the more spread out people are the more roads,
| pipes, etc are required to reach them.
| larsiusprime wrote:
| We're directly inspired by Urban3 and our hope in releasing
| these tools is to enable more people to be able to do this work
| directly themselves and share it with their elected officials!
| chaos_emergent wrote:
| The writer mentioned that people's intuitions about the
| distribution of land and where it's most valuable are wildly off,
| what exactly are people's intuitions that run counter to the data
| presented? It seems fairly intuitive to me that property values,
| as you get closer to an urban center
| larsiusprime wrote:
| Author here: most people know that the city is "more" valuable,
| but drastically underestimate how valuable. I've asked people
| how much more valuable they think Manhattan is than the Bronx
| and they will say things like "5x" or "10x", which is off by an
| order of magnitude.
|
| They also underestimate what this means. In many cities you can
| have 50%+ of land value concentrated in a rather small portion
| of area, and this has huge implications for what would happen
| is you, say, changed property tax policy to shift the tax
| burden towards land and away from buildings. Most people assume
| it would kill the suburbs, but in many of our models single
| family homes come out slightly ahead, or stay neutral.
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