Just Put It On a Map

An underrated strategy for urbanist persuasion, powered by open source tools

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.

The answer is over 100 times. Land value in Manhattan literally towers above everything else. Note that this comparison takes the assessed values at face value—New York real estate is widely known to be under-assessed in general. Nevertheless, the assessed land value of Manhattan is greater than all of the rest of New York City combined.

This isn't just a New York City phenomenon. In Syracuse, Rochester, or Spokane, the same basic pattern persists—the closer you get to the city center, the heart of economic activity, the more land values go exponential. In Cincinnati, we see clusters concentrated towards the Ohio river, with value gradients that quickly decay as you leave the city center.

I have two points I’m trying to make here:

1. People have wildly incorrect intuitions about where land value is concentrated.
2. Putting values on a map is the best way to fix those misconceptions.

This has been an essential part of our advocacy efforts at the Center for Land Economics, and it’s why we built CivicMapper and its companion tool, PutItOnAmap.com (PIOAM).

CivicMapper: Visualizing Urban Potential

CivicMapper has recently been upgraded with a proper landing page and expanded to cover nine cities. The system uses a vector tiles pipeline to transform public open data sources into an internal format, allowing for detailed visualization of land values.

Vacant & Underdeveloped Analysis

A key feature of CivicMapper is the ability to filter and display vacant lots, parking lots, or parcels with very small structures relative to their land area. This is a powerful way to show elected officials how much development potential in the most valuable areas might be going to waste.

Specifically, the tool includes a surface parking analysis. By fetching data from public satellite imagery (NAIP) and processing it with an open-source computer vision model from HuggingFace, the system can identify parking lots that traditional assessor data might miss. This allows us to price exactly how much land value is tied up in parking.

Put It On A Map (PIOAM): A GIS Swiss Army Knife

PIOAM is a suite of free and open-source tools under the MIT License, designed to solve common day-to-day GIS problems.

The philosophy behind PIOAM is to do as much work as possible entirely locally in your own browser, ensuring data privacy. The suite currently consists of four tools:

1. 3D Parcel Explorer: A local-only 3D visualizer for your own data.
2. Data Fetcher: Easily fetch open data from local government sources.
3. GIS Format Converter: Convert between different GIS data formats.
4. GIS File Constructor: Help structure and combine geographic data files.

By making these tools available, we hope to benefit not just those interested in Land Value Return, but everyone in the greater urbanist movement seeking to build better cities.