Thread by @evictionlab

Do you know why your city looks the way it does?

From office buildings to single family homes, #zoning defines what is built and where, including #affordablehousing (or the lack of). But these laws can be difficult to understand. We have a solution. 1/9
evictionlab.org/zoning-restric…

Researchers Matt Mleczko and Matthew Desmond have created the National Zoning and Land Use Database, which allows us to understand how restrictive thousands of cities are in terms of what kind of housing they allow… 2/9

The database includes key measures to understand how zoning works, including, but not limited to, minimum lot sizes, number of units allowed, how much parking is required per unit, and how tall buildings can be. 3/9

All of these aspects impact the cost of housing and how many people can live in a given community, thus having an effect not only on the affordability of a place, but also on its racial segregation patterns, and its environmental sustainability. 4/9

Our researchers also condense all these policies into a single measure to determine how restrictive a municipality or metropolitan area is in terms of its zoning and land use laws. 5/9

The Zoning Restrictiveness Index indicates that exclusionary zoning isn’t just a problem of coastal metros like New York or Washington D.C., but also rustbelt metros like Milwaukee and Detroit. These are the most restrictive metro areas in our database: 6/9

Using previous zoning data, we only had information for less than 40% of the San Francisco metro area, for example.
With our tool, we now have zoning data for 100% of San Francisco. 7/9

Straightforward and nationwide zoning data is key to understanding development and filing the gaps. We hope that these data and code, alongside with other projects like @ZoningAtlas can help researchers, advocates and residents promote more affordable housing. 8/9

For more information on our methodology, you can read the full paper in @USJ_online. 9/9 journals.sagepub.com/eprint/2YGAQ9J…