This story is about 'making pretty' an abandoned building ahead of the ASAE convention but contains a fascinating 'little study' about abandoned buildings in downtown Detroit.

http://www.detroitnews.com/story/bus...asae/31078873/

One can say since 2009 there has been a 75% reduction in the number of abandoned buildings [[meeting a certain defined criteria):

"The good news is that downtown Detroit has far fewer big empty buildings than it has in previous years. In August 2009, the Detroit News counted 48 buildings — structures at least five stories in height or at least 10,000 square feet in space — that were vacant and had no development plan in the works. That number has been reduced dramatically- it’s likely a dozen or less."