Chops and Erosity - Great Lakes Style

[muon2]

While everyone is dissing my Livingston chop map, understand that it is just an entry. If it stays on the Pareto frontier it goes on to a committee of real humans who decide things like whether Saginaw should stay with Midland or if Kalamazoo to Monroe is a bridge too far. They can determine if the South Lyon/Brighton/Howell urbanized area, which is separate from the Detroit urbanized area, means that Livingston can be split off as much as other CSA counties like Monroe and Washtenaw that happen to have an older center that qualified them for their own MSA.

[muon2]

So is this what we can agree to?

The UCC size is defined as the population of the UCC divided by the quota and rounded up to the nearest whole number. The cover of the UCC is the number of districts that include any or all of the UCC. The pack of the UCC is the number of districts that are wholly contained by the UCC. Chop points are assessed for the difference between the cover and size of the UCC, and for the difference between one less than the size and the pack.

I assume that this is in addition to the normal county chop score. If so, I can live with this. I'm not sure I would sign off on this for counties, because I'm not sold on the notion that large counties should prefer having as many whole districts in them as possible. It would certainly be a significant departure from the hashed out definition of a county chop two years ago.

If we go in this direction for UCCs I think we will all head back to our software, since I'm not aware of any of the maps that avoid a penalty for GR.

[muon2]

So is this what we can agree to?

The UCC size is defined as the population of the UCC divided by the quota and rounded up to the nearest whole number. The cover of the UCC is the number of districts that include any or all of the UCC. The pack of the UCC is the number of districts that are wholly contained by the UCC. Chop points are assessed for the difference between the cover and size of the UCC, and for the difference between one less than the size and the pack.

I assume that this is in addition to the normal county chop score. If so, I can live with this. I'm not sure I would sign off on this for counties, because I'm not sold on the notion that large counties should prefer having as many whole districts in them as possible. It would certainly be a significant departure from the hashed out definition of a county chop two years ago.

If we go in this direction for UCCs I think we will all head back to our software, since I'm not aware of any of the maps that avoid a penalty for GR.

Except for the below, I read that as an acceptance of my system, absent the macrochop increment penalty. That still treats fan outs the same, whether the population involved is 40,000 or 300,000. I am not giving up on this one ever, other than via being persuaded it causes map deterioration, or some other negative fallout, that makes such a sliding scale inappropriate, and/or that my scale is too punitive, and the penalty scale needs to be more relaxed. No such evidence of a tangible nature has so far been adduced. Folks just reiterate their bottom line opinions.

I'm not sure I would sign off on this for counties, because I'm not sold on the notion that large counties should prefer having as many whole districts in them as possible.

Really (even with the up to a macrochop pad)? Why? Beyond that, that sounds like discrimination to me. Why should multi county UCC's be treated as sacred cows, beyond the aggregation concept?

If we go in this direction for UCCs I think we will all head back to our software, since I'm not aware of any of the maps that avoid a penalty for GR.

You obviously have ceased looking at my maps.   The problem is, is that this maps generates two erosity points in exchange for avoiding a fan out of GR. If one gets only one more chop point for the fan out, the penalty in this case is pretty toothless. Which gets back to, well you guess it, incremental penalty points! A fan out per our previous maps deserves more than one penalty point. In my system,



 

My bad for missing the map, I obviously fell behind in the scoring of plans as I addressed proposed changes. Too many subthreads embedded in this one.

I guess I really need to see your sliding scale in a table, similar to the one I put together for inequality. Then I'd like clear examples that show the problem we are addressing. I start from the position that the basic definition of chops, specifically county chops, were settled two years ago. If we are reopening that here, the onus is on the party seeking change to demonstrate why the proposed change is needed. You put me through no less to justify macrochops to deal with urban erosity, and I came up with a series of Kent county maps to make my case.

I said I could live with the cover/pack system for UCCs. I don't find it ideal, because then I am back to thinking of them as overlays and not just some kind of super-county. However, if the chop out problem is that severe (and it only seems a mild problem to me), your fix as described by me is a simple enough solution.

I would also caution thinking about direct trades of chops for erosity as you might have above. They are on different scales at present, with a likelihood of 1 chop equal to about 4 erosity in MI, but I lack sufficient data to assert that.

[muon2]

Mike above I posted that you come up with the number of erosity points versus chops that obtains for a state, and that gives you your ratio. You are not reading my posts, and unlike yours sometimes, I think mine are comprehensible.

This is not a litigation, about who came up with what when, and how long something has been in place. Nobody really understood your system anyway - until now. It was basically incomprehensible, or the implications just were not understood. Just pretend your system is being attacked in the public square. Any new system has the burden of proof.

I did read your post, and I don't think that your erosity versus chops will be so simple when actual data is analyzed, and I've said why in replies to others on this thread. I'd love to be surprised and find that it is that simple.

Actually I fervently disagree about the latter. I am no mood to redebate the issue from two years ago. No one had any misunderstanding about how to count county chops at that time. You were even so kind as to mark up a first draft of diagrams that I had tried to draw to illustrate the different ways to envision chops. After so many maps and so many posts back then, now you want to change.

I will happily take my views to the real public square, and I am confident that a view of chops based on how many pieces of a district are in a county regardless of nesting will prevail. I believe it already does in some states such as NJ that counts towns that are served by more than one rep in their reports. The splits reports for districts from the CA commission conforms to my definition of chop pieces for both cities and counties.

I regret that I clouded the original chop definition by trying to incorporate UCCs into the same framework. They are different and will seem so to the public as is apparent from the discussion in this thread. But if my definition of county chops is unacceptable, I will leave it to someone else to score plans.

[muon2]

Torie, my comments were only about what is a chop and how it is scored. Not microchops, not macrochops, just chops. Within the last two days I have said that I can work with microchops counting as chops at the county level and that macrochops need be nothing more than the threshold for using subunits for erosity. This is not about whether UCCs are in or out. I would like concurrence on plain old, vanilla flavored county chops that I thought were agreed to over two years ago when we were drawing plans for CA and other states.

[muon2]

For Michigan for example, it might be useful to draw a map with the absolutely minimum number of chops, using your system as modified, and mine, where we still disagree, and see how many erosity points it has versus say my map, and see what that ratio is.

I feel pretty confident that this map is as chop-minimizing as you can get, vis-a-vis the Torie UCC rules:



Bay, Jackson, and Lapeer are all I-chops.

The Detroit districts are, as last time, drawn to the 47% BVAP standard; another chop of Oakland would be necessary if you wanted to break 50%.

No, it's not a serious suggestion. 

EROSITY: 113 (includes Lansing UCC not acting as a supercounty for erosity)

[muon2]

Isn't it a VRA violation to not put Southfield in a Black district? Either way, I suspect not doing so would be unpopular, even if not illegal.

No, since the only violation can occur if the black population of the area is unable to elect the candidates of their choice. That analysis must be viewed in the context of the whole state, so if there are a reasonable number of districts where the black minority would be able to elect the candidates of choice, it doesn't matter that certain black populations are excluded from those districts.

As a practical matter, that was done in certain legislative districts in IL in 2011. Politically some black communities were shifted to white districts to make them safer for Dems. Major groups representing black issues supported the Dem plan, since politically the Dems would align with their issues, and the number of districts that would elect the candidate of choice of the blacks was not impacted.

=====

This does raise an interesting thought. In our work on southern states we identified counties that had significant black populations, and like the UCCs, thought that they should be grouped together and covered with the minimum number of districts to preserve their voting strength. In principle one could go though the same exercise with county subunits in Wayne and Oakland and recognize those areas as a unique community of interest.

[muon2]

train made an observation that high erosity in urban areas went along with areas with many small munis. I've been updating and making more accurate my Detroit area muni map, with connections. What I see is that the areas with a lot of links that could contribute to erosity are also those areas with a number of subunits with small population, which can often be used to get populations within limits or otherwise reduce inequality. Effectively the higher erosity in that area acts as a tradeoff with lower inequality and seems consistent with the Pareto principle between those measures.

This is the updated map with connections (after a few hours with some mapping software). I've added the Detroit neighborhood boundaries. The blue lines are local connections within counties. Roads on the border count in both munis for connections. The red lines are highway connections across the county lines. Numbered highways on the county border may be used, but cannot be exclusively used to cross the line. That is there must be state highway entirely on each side to make a connection. Otherwise all the munis along the northern border of Wayne would count a connection by touching 8 Mile Rd (MI 102).

[muon2]

train made an observation that high erosity in urban areas went along with areas with many small munis. I've been updating and making more accurate my Detroit area muni map, with connections. What I see is that the areas with a lot of links that could contribute to erosity are also those areas with a number of subunits with small population, which can often be used to get populations within limits or otherwise reduce inequality. Effectively the higher erosity in that area acts as a tradeoff with lower inequality and seems consistent with the Pareto principle between those measures.

Yes, but that only actually has an effect on scoring if the most unequal districts happen to be in those metro areas.  If you have a more rural whole-county district which is leading the inequality derby, the tradeoff in places like Oakland and Wayne and Allegheny is rendered irrelevant, which seems wrong.

Another reason to measure inequality by average rather than simply range, perhaps?

I agree that it lends weight to measurement by average. I'd like to be sure one couldn't get away with one outlier district in population.

[muon2]

I went back to the data set I used to make the table of inequality for range. In that I took as many whole county split states as I could make with the 0.5% maximum deviation and found the average absolute deviation. Like the range it follows an exponentially falling dependence on the average number of counties per district. I then did a regression fit. From that I took a hypothetical state of 72 counties (the average) and determined the expected average deviation one should get as additional districts are added.

Ave Dev	Inequality
0-2	0
2-30	1
30-100	2
100-220	3
220-370	4
370-540	5
540-710	6
710-880	7
880-1050	8
1050-1360	9
1360-1500	10
1500-1640	11
1640-1760	12
1760-1880	13
1880-1990	14
1990-2100	15

For each additional 100 in ave dev, add 1 to inequality. If the average is exactly on the boundary use the lower number.

If this makes sense I can use it in my rescoring of the plans. I can also go to a coarser step size in the table based on the exponential relationship, but I think that is more likely to favor plans with more chops.

[muon2]

A midnight snack for thought:

I'm taking a desultory spin at Florida, for God knows what reason, and... uh... I'm not sure that penalizing for UCC fans is much value added in this state.



That's a fan.  Pity.

(map is very much a work in progress)

If there's interest in going outside the Great Lakes states with their well defined county subdivisions, I should open a new thread. I anticipate different issues in states like FL.

[muon2]

Here's a test case to try to understand the role (or not) of microchops and their potential interaction with single and multi-county UCCs.

MI muon2 2015A


There are no chops except in the big three counties and Detroit neighborhoods are whole. There is an extra chop of the Detroit UCC, instead of in Lansing like with Torie's plans. There is also an extra chop in Oakland to bring CD 14 over 50% BVAP, much like the IRL map. The study is in CD 7, which is slightly under the 0.5% threshold below quota, but within a microchop of the quota.

The neighboring CDs are above quota and could be used to bring CD 7 up. One could move two townships on the eastern edge of Kalamazoo (pop 3276), the southwestern township of Eaton (pop 3150), or Rockwood in Wayne (pop 3289) to make all the districts within deviation of quota.

Without the last shift identified above the CHOP score would be 7 for UCCs, 7 for counties, and 1 for Detroit. That's a low score of 15. It could go down to 14 if a 47% BVAP in Wayne would satisfy the VRA allowing an Oakland chop to be eliminated. For comparison trainB was a CHOP of 16.

But that doesn't include the fix to CD 7. If it is a pure non-scoring microchop, then the above paragraph applies. If it is full scoring chop then it matters which of the three UCC choices I use. In Wayne or Eaton it creates an additional UCC chop as well as a county chop, but in the single-county UCC Kalamazoo, there would be no UCC chop. That seems strange to me. If it gets a fractional score as suggested by Torie, that leaves the question of the UCC penalty up in the air.

Should the three choices outlined above score equally on CHOP or not? Should the fact that it's a microchop matter for either the UCC or the county chop? If it matters, should it only matter for one of the two possible scores?

Edit: It should say 8 UCC chops, not 7. I was focusing on the microchop impact, and forgot to count the whole county chop from CD 8 in the Detroit UCC.

I'm cross posting this here for discussion as to whether this map is good policy despite the chops to the Detroit UCC and whther it should be in the mix of maps that would go to a commission.

On the originating thread I posed a map that required a microchop to complete CD7, but otherwise all chops were in the big three counties. In this version (muon A2) I placed the microchop in Washtenaw in a way to keep Milan intact in CD 7. All other chops are in the big three counties. CDs 13 and 14 are both over 50% BVAP (though CD 13 is 50.02%) and the neighborhoods are kept intact.

MI muon2 2015A2



SKEW 3 (R) [4D, 1d, 4e, 5r, 0R]
POLARIZATION 14
INEQUALITY 11 (range), 13 (ave dev) (range 6021, ave dev 1764)
CHOP 8 raw (UC 9, UP 11, US 12)
EROSITY 119

The chop score remains very low, even with all sorts of UCC penalties. However placing all those chops comes with a cost in erosity despite the nice lines in Oakland and Macomb. Erosity in the urban area remains a strong tool to keep this plan from knocking out others, though the low chop score would probably keep it as a Pareto equivalent of other top plans.

Another interesting feature is the very low polarization score - there are 4 very competitive districts, and nothing completely safe for the Pubs with (only 1 is better than R+3.3 and that one is R+4.8 ). However that competitiveness created a skew to the Pubs since it took a couple of lean D districts and moved them to highly competitive (3 are at D+1).