Brian Olson's approach to Hands-Off Redistricting

I ended my last post with a reference to Brian Olson and the work he is doing to test and implement Hands-Off Redistricting algorithms of various kinds, and the success he seems to be having with his most recent work.  I find his blog fascinating and inspiring to flip through, and I recommend it highly.

Brian is zeroing in on an approach that he finds very promising, and just visually perusing his results – which he makes easy to do by clicking through the hyperlinks here – I think he is on to something. Interestingly, he has applied his algorithm not only to all the state’s U.S. Congressional Districts, but also to all the upper and lower houses of the individual statehouses. His side-by side comparisons between political Hands-On approaches and technocratic Hands-Off approaches is revealing.

The most promising approach, according to Brian, is one that arrives at equally populated districts wherein the average distance between the individuals in the district and the center of the district is shortest. As I understand it from his blog and emails with him, his “least average distance” approach relies on some heuristics and a bit of iteration between progressive passes, and he is still experimenting with things like the definition of “center” (spatial center of the district, or centroid of the population in the district?) but his results are compelling.  You sense the districts trying to take on a taut economy of boundaries which is what I was after in proposing “OPRA”.

Olson vs OPRA guess

Brian Olson’s calculation for California Congressional Districts (left) vs an earlier guess I made for using OPRA (right)

california actual current

What we actually have now in California, even with a redistricting commission. Source:

I enjoyed especially Brian’s analysis of North Carolina, a state whose gerrymandered has been richly abused by others and the topics of previous posts. Here are Brian’s graphic comparisons of Hands-On vs. Hands-Off using his algorithm:

Brian Olson on, comparing current gerrymandered CD's in North Carolina to districts calculated with his algorithm

Brian Olson on, comparing current gerrymandered CD’s in North Carolina to districts calculated with his algorithm

Why wouldn’t North Carolina want to be represented according to the common-sense map on the right?

This entry was posted in Boundary mathematics, Brian Olson, california, north carolina, OPRA. Bookmark the permalink.

2 Responses to Brian Olson's approach to Hands-Off Redistricting

  1. irmabob says:

    Noah, your OPRA is the best scheme I have seen that deals with the devilish details of redistricting. I am excited to post the video on the Facebook page “Gerrymandering-Let’s Get Serious,” which is aimed at the voting public who are furious about gerrymandering and have no leadership on the issue.

    I hope you and others interested in the issue will post to the Facebook page. My goal is to create a movement that is ready to follow highly visible spokespeople (hopefully from both sides of the aisle) who are willing to lead a national movement to end gerrymandering.


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