I am seeing a sudden surge in ghetto population in previously middle class Phoenix neighborhoods. They are coming from as far away as Detroit and moving into foreclosed homes. At first I couldn’t explain it. Then I realized people from inner city neighborhoods from the east wouldn’t move cross country, and especially to a state like Arizona.. unless there were some forces/strong incentives behind it.
This might be of interest to you
http://www.city-data.com/forum/phoenix-area/1146292-section-8-housing-popping-up-all.html