[boxy310]

Also there's a significant problem of infrastructural efficiency. There's research indicating that city infrastructure follows a 3/4ths-power distribution, where doubling the population only increases the need for infrastructure by 68% [1]. The more generalizable format of this is Kleiber's Law [2], which notes that animal metabolisms scale along that same distribution by body mass. The implication is that cities like Detroit that are rapidly contracting in population and per-capita income are getting a double-wammy of decreasing tax revenues and increasing per-capita infrastructure costs.

[1] http://opinionator.blogs.nytimes.com/2009/05/19/math-and-the...

[2] https://en.wikipedia.org/wiki/Kleiber%27s_law