Wednesday, July 06, 2011

Where the price declines are (and aren't) in the DC area

Click on the map to see the full-size version. Each circle represents a zip code. Red circles show places that fell more than the DC metro area average since the peak. Green circles show places that fell less than the DC metro area average.



  1. Very cool map James.  Its interesting to see how the immunozone phenomenon was very much a function of geography for DC. 

    BTW, as someone who bought in Fairfax, while im thankful that our declies were fairly more substantial than in Arl/Alex/DC, I gotta say, im a bit jealous of what I see out your way.  Judging from this map, it seems like Centreville should pretty much be the land of milk & honey.  Are there not alot of deals to be had out your way?  

  2. Nice way to show it, huh...

  3. If I'm reading this right, you put a colored circle at each zip code indicating a percentage of loss.  And a bunch of circles overlap, and the combined color gets darker. 

    So let's make a simple example of two overlapping circles: zip code A and zip code B each have a light green circle, but combined the color gets darker, meaning they fell less.  Conversely, zip code C and zip code D each have a light red circle, but combined the color gets darker, meaning they fell more.

    It doesn't work that way.  In the city centers it's almost impossible to see what color the individual circles are.   A bunch overlap making the colors darker.  So DC gets cumulatively "better" and Baltimore gets cumulatively "worse".

    If this is the case, the map is deceptive and inaccurate. Wouldn't simply coloring in a map of zip code boundaries make more sense?

  4. "Bob See said...If this is the case, the map is deceptive and inaccurate"

    Yes and no.  Your point is taken in that if 2 greens overlap, it does make the area look "greener", but the map is a bit more refined than that:

    If you go to the DC map, there is a feature so that you can zoom in closer so that the circles no longer overlap.  Once done, you can see just how green or red each zip turned out to be. 

    Not to mention, you can also roll over each dot and get a numerical value for drop from peak (i.e. -20.6...-0.7), and get a more accurate read on how much certain areas fell from the peak. 

  5.  Ahh, I didn't see that interactive map, thanks!