This is the sort of topic I suspect has been written about elsewhere, just nowhere I can find through some preliminary Googling. Like many urban neighborhoods, my neighborhood of Shaw has been gentrifying slowly for a number of years after experiencing heavy disinvestment in the 1950s and 60s. That means many blocks contain not only vacant or abandoned structures but also newly renovated and owner-occupied buildings. During a tour of the neighborhood last fall the leader of a community development corporation commented that many of the structures which look unremarkable from the outside (plan, sometimes neglected facades) are actually nicely redone and occupied inside.
Thus the overall feel of many blocks is inward-looking: fully utilized structures look vacant an unadorned, trying to blend in. Most do not have much outside lighting, present fortified doors to the outside world, and have heavily shuttered windows. Other neighborhoods in more prosperous areas have a totally different, outgoing feel: most homes have outside accent lighting, doors and entranceways (however secure) are made inviting, and fewer windows are visually sealed. In both situations I assume the decision is based both on a perception of safety and also the general expectations set in the neighborhood. While I understand the impulse that leads to either situation, I wonder at what point a neighborhood reaches a tipping point. Is it dependent on decreased crime, or does the switch happen when a critical mass of image-conscious residents and businesses is achieved? Perhaps it is time for me to read the book with that title and try my hand at applying its ideas to urbanism.