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[personal profile] angledge
Ha ha! Data processing is finally finished for the 108th Congressional district map of Pennsylvania. 480,979 census blocks, sorted into 19 Congressional districts. Now that my data is in place, time to start getting the algorithms running ....



Senator Rick Santorum, I blame you for this mess.
Here's a GIF, created in MS Paint from a TIFF exported from ArcMap.

Senator Rick Santorum, I blame you for this mess.
Here's a PNG, created in MS Paint from a TIFF exported from ArcMap.

just for local interest

Date: 2004-06-25 11:04 am (UTC)
From: [identity profile] angledge.livejournal.com
Here's a closeup of the Jenkintown area. I especially like the strange appendage of District 8 that snakes down from Bucks County into Upper Dublin township. Also, notice that the tiniest bit of the Southwest corner of Jenkintown is in District 2.

Image

Re: just for local interest

Date: 2004-06-25 07:05 pm (UTC)
From: [identity profile] krick.livejournal.com
Do the boandary lines follow rivers or roads? That might explain some of the strangeness.

Re: just for local interest

Date: 2004-06-25 07:26 pm (UTC)
From: [identity profile] krick.livejournal.com
It just occurred to me that they might be following zip code boundaries.

In auto insurance, the whole state is divided into "territories" that are gerrymandered by the insurance industry to group highest risk areas together. In Pennsylvania, this results in things like this description of what comprises territory 01:



It's almost impossible to know what territory you live in. Imagine you were planning to buy a house and wanted to live in one of the "cheaper" territories. Good luck.

In California and a few other states, the people got fed up with this crap and made them change it all to a zipcode based system. As a result, boundary lines are a bit jagged.

Re: just for local interest

Date: 2004-06-26 01:11 pm (UTC)
From: [identity profile] angledge.livejournal.com
The lines generally follow the boundaries of the census blocks. But they do so with discretion - after all, there are 480,000+ blocks & only 19 Congressional districts. So, which blocks get placed into which Congressional districts? That's the heart of the gerrymandering exercise. Gerrymanders use Census data & GIS software to tailor-make districts with certain characteristics - they use data such as previous voting results, party registration lists, even stuff like magazine subscriptions to guess how many Democratic/Republican voters live in each Census block. Then they group together Census blocks to give their party the competitive advantage.

Re: just for local interest

Date: 2004-06-27 06:44 pm (UTC)
From: [identity profile] d4b.livejournal.com
Thanks! I'm having trouble finding an appropriate political map to match up details, but from what little I can derive, it'd seem that Jenkintown's borders themselves might be a bit of similar manipulation. Maybe I'm too cynical, but... that little bump in the SW corner would seem to correspond with that private bank (whose name escapes me at the moment) which only has a few hundred clients, but each one meeting their $5 million minimum account requirements (or did they poor-down recently and drop it to $2MM?). You probably know of the institution of which I speak; it's essentially a private bank primarily for the Pitcairn family. If my hunch is true, Jenkintown would get the corporate taxes, but Cheltenham would "get" the votes (not that anyone actually lives at the bank, so it's a non-issue). Similarly, that little bump on the SE corner is probably the Pavillion, although I always thought that that was in Abington township and only a Jenkintown mailing address. Again, that'd seem to be a huge tax revenue source.

Re: just for local interest

Date: 2005-11-19 01:36 am (UTC)
From: [identity profile] angledge.livejournal.com
Re-adding the graphic after the linky broke:

Image

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