There are two forks to Broken Window Theory, one of which deals with property and the other of which deals with society. The side that liberals love to pick on is the side that Rudi Giuliani used to crack skulls all across Manhattan. The side that sociologists pick on less is the one relate to graffiti and litter.
But, I mean, all roads lead to Zimbardo and there are no looser cannons in psychology. But when the theory was proposed in the Atlantic, they were using the "common knowledge" that buildings with broken windows end up with more broken windows and then extending it to criminology.
It ends up being a chicken-egg problem, and that's why I asked - spaces that people are invested in, they improve. Places that they don't invest in, they don't. My read on the article is that a space needs to be above a certain threshold before people will invest in it and the threshold, from my read of the study, was not conclusively found, thus my question.