Check out this article from NextCity.org:
Interesting thoughts here, as we can visualize this through the lens of Philadelphia. We often speak of the “Urban Renewal” phenomenon in the 1970’s as a mistake, but are we still making those same decisions now? This issue is easy to see in large, sprawling cities but even smaller towns should take a look at their historic properties.
Full link to the article: http://nextcity.org/daily/entry/a-lot-of-tiny-pieces-lost-historic-preservation-vacant-properties