Alright, here's a follow-up to the recent map of vacant housing rates according to the 2010 US Census. This map compares the vacant housing rates from 2000 to the newer data of 2010; the difference between these two proportions is mapped here:
Post Scriptum: There was a lot of interest (as far as this blog's level of activity goes) around what in the world a vacant house actually is. The gut reaction for many folks, including myself, was that vacancy is a pretty clear indicator of economic decline -shuttered houses left to rot. BUT, mixed in with that very real set of feral houses are houses that are vacant because times are good: vacation or seasonal homes whose owners happened to be occupying some other abode at the time of census canvasing (you can, after all, only be in one place at a time). Also, there is the more neutral condition of a home that is about to be moved into. I found this crusty old PDF to be the best description yet.
So, the characteristic of these houses is pretty broad and not necessarily negative. But whatever the reason, they were deemed vacant -and this is a map of that deeming which you can take for whatever it is worth.
Double Post Scriptum: It sure would be great to find a clear, unified, un-obfuscated set of HVS data for counties, in order to break these phenomena out.