ACM, of A Smoke Filled Room, pointed out an interesting study yesterday:

Amidst all the discussions about how to encourage but direct/control development of city neighborhoods, one thing often goes unspoken: that the low-rise "character" of Philadelphia, with its row-houses of 2-4 stories, represents a long-term constraint on growth and modernization of the city as a whole. All the more reason for the city to make some central plans about neighborhoods to protect, regions where taller buildings would fit in better, areas needing complete redesign, and the like.

Anyway, was made to think of these issues while reading this Harvard news article, which reports that experts think that density is critical to urban vitality.

In some ways, this idea is pretty obvious. In dense cities, especially in the Northeast, you can almost "feel the electricity" or whatever; much of it because people are simply on top of each other. I spent 4 plus years in the Twin Cities, and while they are wonderful places, there is a palpable difference in cities that are spread out over a much larger geographic area.