This is very cool. I don't know much about Philadelphia, but I'm interested in how much this reflects/affects rental trends -- would people move from a higher-taxed property to a lower one? Are the taxes increasing in areas with less crime? Are the taxes increasing in areas where elected officials live?

Looking at the way this is done, it seems like the hardest part of doing this for another city is getting accurate geographic and valuation data in the correct formats.

I'm not the reporter on the project, but from what I've heard in the media, it sounds that renters are supposedly the biggest losers -- some properties are seeing thousands of dollars in tax increases, which they'll most assuredly pass onto renters in a tax hike (my opinion, also that of some other Philadelphians). Related article: http://www.newsworks.org/index.php/local//taxipedia/51402-ar...

assuredly why? is rental pricing competition purely cost-driven?

Since rental units don't have much marginal cost, that seems unlikely -- They are capital investments, financed by mortgages or owned outright.

Great maps. I'm curious if anyone has information about the tax plan in question. It seems decidedly regressive. For instance, the taxes on this dump (http://goo.gl/maps/Fm3sT) are going up to $1230, while the taxes on this place (http://goo.gl/maps/ubtzA) will be $10743, even though the latter place's assessed value is 50x higher.

Philadelphia City Paper's Isaiah Thompson has been covering it for quite some time.

A quick summary:

The Nutter administration is asking the city's legislative body to pass its Actual Value Initiative (AVI), which would base property taxes on a city-wide reassessment that is supposed to fix years of screwy property values across the city. Many residents would wind up with a lower property tax bill, but many – including longtime residents of more affluent neighborhoods – will pay more, in some cases much more.

http://www.citypaper.net/blogs/nakedcity/Behind-the-curtains...

http://www.citypaper.net/blogs/nakedcity?search=y&search...

The impetus behind the AVI is to "value at market rate" -- the idea is that by updating the valuations, they'll eliminate the unintentional tax break/overcharge some people were getting.

A funny thing about gmaps and Philly -- Philly's changing so fast that that 'dump' is probably a new renovation by now. The building I live in now still appears on Gmaps in its unrenovated state.

Regardless of whether it remains a dump or doesn't, the reported valuation of the dump for 2014, according to the linked application, is $92k, while the nice place has a valuation over $5m. So the dump is paying over 1% while the mansion is paying .2%