# Invisible walls

By [Brandon Donnelly](https://brandondonnelly.com) · 2018-09-13

cities, colombia, density, invisible-walls, manhattan, marron-institute, new-york-city, new-york-university, nyu, population-density, uncategorized, urbanism

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[This](http://marroninstitute.nyu.edu/working-papers/invisible-walls) is an interesting working paper by a team of researchers at NYU’s Marron Institute of Urban Management. The paper examines the relationship between urban density and organized violence, first in Colombia and then within a sample of 200 global cities.

The finding is that organized violence actually increases the population density of the surrounding areas within a city because it creates a kind of “invisible wall” – effectively a no-go zone.

This makes perfect intuitive sense, but it’s not something I ever considered. Geography and other natural constraints typically drive density. Think about the island of Manhattan. But so too can invisible walls.

For the full working paper, [click here](http://marroninstitute.nyu.edu/working-papers/invisible-walls).

_Photo by_ [_Joel Duncan_](https://unsplash.com/photos/Iqa-WlbNjqs?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText) _on_ [_Unsplash_](https://unsplash.com/?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText)

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*Originally published on [Brandon Donnelly](https://brandondonnelly.com/invisible-walls)*