US House Redistricting: Minnesota

[Torie]

Hard to argue with those maps Mike. In short, they are as boring as hell! 

[Torie]

Hard to argue with those maps Mike. In short, they are as boring as hell! 

I doubt it will happen. In the last map the Courts argued about the relevent merits of having an outstate district span either all of Southern Minnesota, all of Western Minnesota, or all of Northern Minnesota. The court claimed the facts pointed to the Southern span being the preferable partition.

To swap the South Western corner of Minnesota would reverse that decision.

Population trends in MN-07 vis a vis the balance of the state, and where the county lines are, makes that a tougher sell now, I would think. The 1st to get to the SW corner of the state would have to be a thin as a pencil.

[Torie]

Admit it BRTD, the main thing you care about in MN is just putting Rice County in MN-1 right?  You should have studied harder and gone to Carleton College.  

Edited by an alum

[Torie]

Back in January on this thread I speculated on a plan with minimal changes. This assumed that the plan would be drawn again by the court. Since the Gov vetoed the GOP plan, I've updated my earlier map to reflect the actual 2010 populations. Drawn at the VTD (precinct) level, this map has a range of 99 and a maximum deviation of 56.

I took a crack again at drawing a least change map that I thought made some sense, without looking at Muon's map above. I wonder if my variations from Muon2's map are due to different population numbers. I used Bradlee's 2010 election district numbers that are on his utility.





And another chop between MN-03 and MN-06, which might make more sense:

[Torie]

The Dems did a butt ugly tri-chop of Hennepin it appears. Surely that dog won't hunt would it with a court? I don't see the Mankato chop myself.

Both parties would have done themselves more good with something more realistic. A court simply is not going to do a great northern CD on its own recognizance, unless it is a Pub controlled court, with a partisan bias. The Dem map appears to be a joke.

[Torie]

Myself, I would tolerate some cuts if that means a better tying together of communities of interest. Thus MN-05 going farther north into Anoka, seems undesirable to me, even if it avoid a municipal cut. Life is a balancing test. No one factor should reign supreme.

[Torie]

BRTD, the part of Rice that Waltz got went 51% McCain. Klein kept Northfield, which is where the Dems really live in Rice, hanging out in that academic college town. The county seat isn't that Dem.  It looks to me like MN-02 went about a point or two Dem, and MN-01 went the opposite way by somewhat less (the exchange of territory there is all about 51% McCain, so the move to the GOP would be limited to whatever increase in population it got). MN-08 and MN-07 get a tiny bit more Pub.

[Torie]

Yeah and the area that Walz lost to the west is more Republican than anything he gained. But I tried drawing this in DRA, and the partisan change to the first is basically statistically negligible. So Walz is fine, but we all already knew that anyway (it's not like major changes to the district were ever geographically possible anyway)

McCain carried that western salient by about 600 votes. But yes, the change is negligible.

[Torie]

Here are the stats.  Everything gets more Pub except MN-02.

[Torie]

Here is a map for 7 CD's in Minnesota using 2010 population figures this time, rather than projected 2020 figures, just to make it easy. If you really focus on erosity, trying to limit chops, but only doing so if it does not materially degrade erosity, or chop metro areas, my suspicion is that typically there will be but one or two maps really in the hunt in many states. Certainly, Minnesota seems to be one of them.
This map has 3 county chops (Anoka, Wright, and Hennepin), and no locality chops. The trick is to come up with the set of rules, that forces these kind of maps to be spit out of the black box.

[Torie]

One chop into the twin cities metro area (say to take Dakota), in exchange for "freeing" 3 more rural counties from metro domination, and less erosity, is a fair bargain, but having two CD's chop into the metro area is not in my view, and you have Scott and Carver bit off by a separate CD.

I think my "clean" chop into Wright, taking that portion that really is part of the metro area, in exchange for considerably less erosity in the north portion of the map, is a more than fair bargain myself.

I had a couple of more map potential iterations to consider (one where MN-04 nipped off Chisago, and Washington County was bifurcated (that chop is a negative; nasty county chops need to be scored as a negative in some way, so the black box seeks other alternatives if they are reasonably out there),  with MN-02 losing its three southern rural counties), but the program crashed. They may surface later if the stars are aligned right.

Again the point is to have a total point score, so all of these sometimes inconsistent considerations can be reasonably balanced off against one another by the black box. No one factor can be the dominatrix.

[Torie]

Maybe the way to parse this is that using the Census definition as a safe harbor, but if its chopped, no negative points, if the carve out is a low density area, and the metro area just sucks up low density areas of counties that are rural, or whole counties with low density, like Sibley, if the Census counts that. The computer should be able to have density data loaded into its data bank.

I consider our respective MN-06's to be close in erosity measures - but then I like rectangles rather than irregular shapes, and your MN-07 is more erose. Both maps should get high scores, and I agree that where they are out there for the black box to generate, it is good to have more than one map to consider, provided the vetting process is not gameable, because the pros have some say in the process. I don't like these so called non partisan commissions. They have tended to be relative flops so far.

Anyway, here are a couple of other three choppers that might be in the hunt, although the Pubs might nix the first one. The first map has the Sherburne conundrum, the county that takes a bite out of both the St. Cloud and Twin Cities metro areas, so one metro area or the other will be chopped. Most prefer that it be in the St. Cloud zone, because St. Cloud crosses the river into it with about 3 precincts, I understand. But that alone should not be a deal killer.

Muon2 and I seem to both be viewing county trichops as a negative, even if the total chop count is unchanged it appears. That is another factor to consider whether or not it should have separate weight.

 

[Torie]

Oh, if county lines are irregular, than you can't draw perfect rectangles (and I haven't drawn perfect rectangles, just some reasonable facsimile thereof), and a long thin rectangle is not good either (and I don't do that either - well MN-01 sort of is, but that CD tends to be bit of a pain in the butt due to population and geography issues (e.g., both of us would rather lose our package then have a non metro chop in MN, and to avoid that for MN-01, the options narrow down, simply because the little counties don't have quite the right population numbers to get something less erose not using a metro county, but without a chop; we both drew maps that make MN-01 more compact, but at the cost of nipping off a metro county )).

Anyway,  the computer program if well done will "fairly" score out the balance. Back, and back again, and yet again,  we come to that irksome balancing test. You're the brain, and I'm the trouble maker - figure out a magic formula to get the balancing test right, so it meets the I know it when I see it (excessive erosity vis a vis the alternatives) test.

The density issue can be put into the software, and the software will tell you where the zone is, that can either be part of metro CD's or no, without penalty. There are not enough folks in the grey zone, to make that much of a partisan difference, and if it does, and skews the partisan profile, then one party or the other will nix that map. But most times, neither party will care that much about that particular issue, nor will the residents. So if having a grey zone, helps with compactness, while not allowing making metro areas a free fire zone, then life is beautiful.

Anyway, below is a three chop map that is just gloriously relatively compact, and keeps the metro area as tight a drum almost, but has that trichop of Hennepin (2 chops for Hennepin, and one for Anoka).  This issue needs to be resolved.

[Torie]

The chop of Wright out of the metro CD's is negative in my map. I don't pretend otherwise. However, if a metro chop generates enough positive points otherwise, it may be worth it. Such a chop is needed to get the erosity of MN-06 or MN-01, or both, down. But to ignore the factor entirely I think is a mistake. It might exclude otherwise worthy maps, or include unworthy ones, for consideration. Wright is one county by the way, where part of it per density factors, is in the metro area, and part is not. So chopping it in the right place (as my first map did), would remove it from counting as a metro chop. Severing off Isanti and Chisago should not count as metro chops at all, nor should their inclusion in metro CD's be viewed as a negative either. Those two counties swing both ways as it were. They and western Wright are in the grey zone. Ditto south Sherburne.

I don't consider something closer to exact equality superior to something less exact, provided the 1/2% rule is hewed to. Using the pad, helps to reduce erosity, keep municipalities together, have straighter lines in county chops and so forth. Having free rein to move around 6,000 folks or so between CD's is the reason why that I suspect none of our maps has any locality chops. And it will generate more reasonable maps from which to choose, without having much if any partisan effect. The computer should have that flexibility. I don't consider having something closer to exact population equality as much of a public policy goal at all. Each and every other consideration out there is more important than that to me.

And we still have the trichop issue that you did not address in your above post, which was the primary reason I put up the latest map! 

[Torie]

Yes, your map above is a fail on the erosity measure. It's close to hideous actually (for example you took the weakest part of one of my maps (the elongated MN-02), and just stretched it out some more, and out of the metro area entirely into Pine County (not sure how you did that, since all you lost was a small chop into Ramsey, but whatever, and if that is what it takes to avoid a chop, it's just not worth it - that balancing thing again). Sure if two maps get an equal score, the one with less of a deviation in populations is better no doubt. But such equal scoring is a hypothetical that probably will not occur. If a variation will smooth out a line, or reduce erosity, I'm for it. You seem more interested in chop counts, and road connections, than erosity per se, or smooth lines for that matter. On that one, we are just not on the same page at all. You are just not into visual tests;  I am, that is what folks actually see. Sure you need an algorithm to score erosity, that is compatible with the eye test, and so far, we are not making much progress in generating one - at least one that pleases me. That just does not seem to be your focus.

In any event, a black box generating population deviations following factors that have a reasonable basis, will be just fine with the courts. On that much, I am confident.

Anyway, for what map, or maps, do you want my deviations for?  I guess you have a right to do your own thing, of course, even if I think it is largely a red herring. You don't, so that is that.

[Torie]

Well we agree on a point system. If population inequalities don't generate more points, it would be hard to defend. But if it does, it's OK by me. Then the deciders based on some strike system can pick one of the high scoring maps. I would be amazed if a court rejected a high scoring map with a slightly higher population deviation than another map with less population deviation given such a process. And obviously this fact pattern has not been before the courts. The point is, is that given one approach to a map, if the population inequality is a point generator and thus has a legitimate reason, for the court to reject that in favor of a another approach picked by the deciders from an array of black box generated maps, would be court intermeddling at its worst, and I just don't see that happening. So on that aspect, we just disagree absolutely.

Surely you don't think the court would pick a plan  with less population inequality but with a higher score, than a map with lower population inequality do you? That would be insane. I guess what I really disagree with most, is giving points to a map with less population inequality, so that map gets pushed ahead even though otherwise inferior. That really offends me.

[Torie]

Oh nothing is absolute I suppose Muon2. But any system that allows a "discernible" amount of additional erosity for slightly more population equality, or forces a significant amount of additional erosity to avoid a chop, I think is flawed. We don't want to get a map from Dakota to Pine as being on the top of the heap absent highly unusual circumstances. I want erosity to have the most weight, chops next, with population at the bottom of the list.  How do you count population inequality? The sum of the amount of population of all the CD's that is above or below the perfect number?

I keep trying to focus on the practical, while I think you are trying to focus on the perfect, and what comes out leaves the madding crowd unhappy.

In your analysis of my map, were using that road chop thing again, that I can't understand very well, and I don't think you have sold anybody on? If we are going to generate more erosity to avoid road cuts, we are in trouble. (I did say I might be willing to count as a chop appending a county that has no state highway link to the balance of a CD.)

[Torie]

In your analysis of my map, were using that road chop thing again, that I can't understand very well, and I don't think you have sold anybody on? If we are going to generate more erosity to avoid road cuts, we are in trouble. (I did say I might be willing to count as a chop appending a county that has no state highway link to the balance of a CD.)

My analysis of your map used a much simpler measure that usually gets the same ranking of two maps. Roads aren't considered at all for this measure.

Each county in the district counted the number of counties it bordered in other districts. Chopped counties count as separate counties for this measure. Add that up for all the counties in the district and you have the total I listed. Add up all the the districts and divide by two to get the total.

For example CD 1 in your map I counted 17 as follows:
Faribault (1): Martin
Blue Earth (3): Martin, Brown, Nicollet
Watonwan (4): Martin, Jackson, Cottonwood, Brown
Le Sueur (2): Nicollet, Sibley
Scott (5): Sibley, Carver, Hennepin W, Hennepin E, Dakota
Rice (1): Dakota
Goodhue (1): Dakota

The method is functionally like measuring the perimeter which is a good test for erosity. The use of roads is introduced to remove contiguous stretches like Watonwan-Jackson that have no convenient means for travel between. Its advantage over a perimeter measure is that it is immune to wiggly borders due to rivers and it gives a simple count that anyone readily compare when considering how chops affect erosity.

Ah, Mike, below are two map options for the state of Atlasia. Each color represents a county. It has two CD's. Roads connect everything. Which map is more erose - the top one or the bottom one?

[Torie]

Top obviously, not that bottom is great.

Your point being that it is technically possible to construct fantasy examples where the number of such county/district border matches is not just slightly but very much off?

Yes, probably for Midwest grid county arrangements, of roughly the same size, and lined up, Mike's little system is a pretty good proxy. But it can go seriously wrong, with odder shaped counties (the specific problem being you get screwed if a big county borders a bunch of little ones in another CD, as opposed to another big county, even though it may have no impact on erosity whatsoever, except in Mike's world ). I would rather avoid proxies, and go for the real deal, which relates to perimeter lengths, and how much of a CD fits into a perfect square. Fitting into circles isn't great, because God made most counties into rectangles, not circles.

[Torie]

I will try to parse through you post Mike, but in the meantime, it is true is it not, that your system counts the more erose plan vis a vis anyone's common sense, as in fact considerably less erose?  We need to peel back the layers on the onion one at a time.

[Torie]

I will try to parse through you post Mike, but in the meantime, it is true is it not, that your system counts the more erose plan vis a vis anyone's common sense, as in fact considerably less erose?  We need to peel back the layers on the onion one at a time.

My post is to point out that what your eye sees as more erose is not necessarily so when measured by known algorithms designed to promote square districts. That my novel technique (from an idea by jimrtex) also classifies them in a similar way does not indicate a weakness in my system. It points out what is well known - it is hard to bias against C-shaped districts in favor of L-shaped ones without creating all sorts of other problems.

The thought behind my method is anything but pursuing the perfect. It is in recognition of the weaknesses of more detailed algorithms that I went for a KISS approach. I'm willing to preserve that same weakness in the name of a simpler method. It's one that anyone with Google maps can check. Your examples illustrate how simple the method is. The only part that I need to tune in my method is how to measure chopped counties. That's a task I'm actively pursuing.

I guess I will accept that deflection of my question as an admission. Thank you. In any event, it is not just my eye, it's almost everyone's eye (you, you math/physicist person happiest when caressing the supercollider like a pedigree dog,  just see the beauty of the algorithm as overshadowing the bestial veneer, when maps are all about two dimensional veneers. Can you detail in a clear way, just why any cure to get the box to match the eye, is a fool's errand, with the cure worse than the disease?