Local vs regional road connections

[muon2]

I generally like your changes to my map. I was drawing it in a hotel room and I'm sure I missed things. I didn't have to chop any munis to put Vashon in 7. I think it was just Vashon, Seattle, Shoreline, and perhaps one next to Shoreline. I can't check from the car, and I could easily have missed something there.

What you did in your map with King and Pierce I believe should have no penalty. We never faulted it during our extensive work on MI, and I don't see why we should now. I think that is where we fleshed out these county chopping rules.

The problem with muni chops in WA is similar to what we encountered in MD, NC, FL and other states that lack subcounty government. Some of the places in WA on DRA are incorporated places, but others are not. I would not want to give particular importance to unincorporated place lines, since they don't have to reflect real boundaries. We could use the Census CCD boundaries in WA counties, much like using the MD election districts. However, in King they are mostly too large on the west side, so they would need to subdivided based on incorporated munis. Defining the subdivisions in King and Pierce are a necessity to look at connections and erosity.

The network map I posted was in my Atlas gallery that I found through a search. I created it in 2012 using Visio. It was for a thread about connections and regions in WA that had a lot of back and forth between jimrtex and I. Our differences about connections in NC can be visited in that thread three years ago. We really keep crossing the same ground on these issues, but I tend to resist wholesale thread necromancy so here we are.

I'm pretty sure I found WA 261 crosses the Snake river from Franklin to Columbia back in 2012, if that is your question. The paper atlas in my car shows it that way, in any case.

[muon2]

The problem with muni chops in WA is similar to what we encountered in MD, NC, FL and other states that lack subcounty government. Some of the places in WA on DRA are incorporated places, but others are not. I would not want to give particular importance to unincorporated place lines, since they don't have to reflect real boundaries. We could use the Census CCD boundaries in WA counties, much like using the MD election districts. However, in King they are mostly too large on the west side, so they would need to subdivided based on incorporated munis. Defining the subdivisions in King and Pierce are a necessity to look at connections and erosity.

Yes, I agree with all of that, and am inclined at this point, absent something persuasive, to follow the precinct nest rule. But in individual states there might be a good reason not to do that, and the state should just change their precinct lines. But the fact that the precincts are not nested, suggests the states with that syndrome don't care much about the integrity of such localities. The same might obtain for city neighborhoods. It would be a lot to ask for say NYC to have to change its precincts wholesale to accommodate your idea of what and where the neighborhoods are. But if the precinct lines follow the neighborhood lines, great. Bremerton is an incorporated city. You just missed its erosity on the south end. No problem. It's just that you so rarely make mistakes, that I tend to think what you do is deliberate. In this case, I thought it might be a pavement obsession.

This is the issue most germane to the thread. WA generally has precincts nested in cities and towns but not Census places or incorporated towns (all of which have the same marking on DRA). Precincts for cities seem to have either a name or prefix number to indicate that they are from that muni, but I've found some exceptions.

The most important property of county subunits is that they must cover the whole county. That means the all the non-city areas have to be accounted for.  My sense is that we are using cities where there are nested precincts and single precincts everywhere else. That's a lot of county subunits, but one can usually extract it from DRA. Using them as subunits for erosity will tend to make higher scores in the areas defined by individual precincts.

jimrtex suggested school districts which in King look like this.

They aren't so numerous that they would run up erosities, the public has a strong sense of being in a particular school district, and they aren't going to change at the whim of the county board. However, it doesn't look like they line up with the DRA precincts. The best we could do is make an approximation of precincts to school districts.

What works best from your perspective?

[muon2]

To guide our thinking, I put together a map of King with the incorporated munis from 2010 colored in. This image shows most of eastern King including the place lines from DRA. There are over 320K people in the unincorporated parts, so they need some reasonable assignment to function as county subunits.



It's clear to me that any hope of precinct nesting will fail for anything other than incorporated munis. In order to test the metric I need subunits for erosity. Therefore to avoid a profusion of precinct sized subunits, there must be precinct aggregation, even if it is only approximate.

Muni growth in King is driven by annexation, and the county actively encourages built-up areas to annex to an adjacent town. The King web site includes descriptions of potential annexation areas that it is promoting. Since 2010 the area north of Kirkland got pulled into Kirkland doubling its pop. There are a half dozen current PAAs (potential annexation areas).

The area east of Renton is a PAA that rejected annexation in a 2007 referendum, but the county is still pushing it to get greater efficiency of services. Note that a bit of the PAA has already been pulled into Renton.



Are these useful for creating county subunits?

[muon2]

I see you continue to think about this. So do I.

If we can't find a complete set of subunits for a county then erosity can work in one of two ways. either the chops are treated simply, as we do without a macrochop, or they have additional connections to adjacent counties. Either way the only connections within the county are those from the whole of an adjacent CD. Let me use my map for King and its environs to illustrate. The primary connections are the ones that would appear for a simple chop. The secondary connections are those due to state highway crossings other than the shortest route between county seats.



CD 7 connections 4/5
Primary:
King-Kitsap (6) via Southworth-Fauntleroy ferry
King-Snohomish (1) via I-5
King-King (8 ) internal
King-King (10) internal
Secondary:
King-Kitsap (2) via Seattle-Bremerton ferry

CD 8 connections 6/7
Primary:
Snohomish-Snohomish (1) internal
King-King (7) internal
King-King (10) internal
Kittitas-Chelan (4)
Kittitas-Grant (4)
Kittitas-Yakima (4)
Secondary:
King-Snohomish (1) via I-405

CD 10 connections 3/3
Primary:
King-King (7) internal
King-King (8 ) internal
King-Pierce (9) via I-5
Secondary: none

Excluding the double counted connections between the three CDs the total erosity is 10/12. CD 8 and 10 are both D+8.

So consider this Pub attempt to give themselves a shot at a CD. All the munis are kept intact and things are connected. CD 10 grabs all the Dem suburbs next to Seattle and becomes D+13. CD 8 becomes D+4 and the Pubs carried it in 2010 for US Senate 51-49.



CD 10 looks very erose to my eye, but let's check the score without the benefit of subunits.

CD 7 connections 2/3
Primary:
King-Kitsap (6) via Southworth-Fauntleroy ferry
King-King (10) internal
Secondary:
King-Kitsap (2) via Seattle-Bremerton ferry

CD 8 connections 6/7
Primary:
Snohomish-Snohomish (1) internal
King-King (10) internal
King-Pierce (9) via I-5
Kittitas-Chelan (4)
Kittitas-Grant (4)
Kittitas-Yakima (4)
Secondary:
King-Snohomish (1) via I-405

CD 10 connections 3/3
Primary:
King-Snohomish (1) via I-5
King-King (7) internal
King-King (8 ) internal
Secondary: none

Excluding the double counted connections between two of the three CDs (7 and 8 aren't connected) the total erosity is 9/11. This plan is better on regional erosity than the first plan regardless of the method used. There's nothing in this counting to penalize the gross shape of CD 10. Yet it does matter politically. This is why macrochops need subunits - to judge the shape of urban districts nested in a big county.

[muon2]

But I will get into that dealing with your King County map on that thread. On that map, did you count non state highway road cuts between municipalities in separate CD's that do not involve another county? I ask, because in general, the county chops are incentivized to go where fewer jurisdictions exist, which would tend to help the Dems because it is less populated areas that are chopped. In general, if one CD takes in the more rural areas, and the other CD takes in the populated areas, you will have one CD appending inside a county a ton of localities, with a lot of road cuts. Each and every road that leads out from a municipality to the balance of a county, even if there are no sub jurisdictions in the balance of the county, would count as a road cut. So that issue needs to be resolved first.

I'll reply over here.

The method I used to assess erosity in the King example was the one that was initially developed and applied in our exercise in AL and other states back in 2013. That only counted at most one connection between pieces of different districts within a county. We thought about applying townships in all cases, but an initial look at minor chops in OH showed that counting all the connections between townships/munis in a chopped county overly penalized those minor chops. However, something was needed to deal with dense counties like Cuyahoga where erosity could only be measured in terms of adjacent munis.

When we came to MI we dove into detail on when those connections between munis should apply. The preferred metric was to define a macrochop then apply the subunit connections only in those counties subject to a macrochop.

The essence of this erosity measure relies on having every parcel assigned to a division. For example every parcel in a state is in a county or equivalent so erosity at the county level makes sense. In MI every parcel in a county is in a township or muni so again the metric works appropriately. What we are trying to do is accommodate macrochopped counties in states where not every parcel is in a township/muni.

A big complication is that you only want subunits that reflect preexisting precinct lines. However, as I look at various state statutes I see it's usually the opposite from the direction that would work best for you. The precincts are updated to conform with political units after redistricting, not before. The policy reason is to reflect any new chops with new precinct lines.

In King there are munis but not every parcel is in one. I did not consider muni-muni erosity because I don't have a metric to define a connection when there is an unincorporated gap. For example there is an unincorporated gap between Kirkland and Bothell on my map. The gap was small enough that today they are contiguous, though they weren't in 2010. Either way, a meaningful erosity needs to assign that 2010 unincorporated area to a subunit.

[muon2]

My first problem here before we get going further, is that I don't understand your road cut count. Talk about complexity! It would seem to me the cuts generated between counties would tend to be the same for any map, where in the adjacent county another CD exists. So we are left with cuts internal to King County. In playing the game myself to minimize highway cuts, I drew your WA-10 much the way you did. Assuming non municipalities were deemed but one jurisdiction in King, we have a highway cut between Renton and Newcastle, Renton and the unincorporated area,  Maple Valley and the unincorporated area, and then road cuts however counted where the unincorporated area is chopped, which is any pavement correct? That would be a nightmare to count potentially. And you think tie breaking preference rules are complex and hard to apply (which even someone as obtuse as I think are quite simple and straight forward)!

Anyway, the incentive would be to have the CD line follow the Cedar River to minimize such cuts I suppose, and adding a road cut for Black Diamond, per the map below. Although you might say Black Diamond is not connected by a state highway so that is off the table, but I don't agree with that rule either with respect to internal cuts in a county. Any pavement will do. Anyway, it seems the the road cuts internally are quite low.

Of course, with my bridge chop definition and rule, the posited Pub temptation that is alleged to be doable with a winning score would be off the table, but I digress. It appears that we may permanently part ways on the bridge chop issue. Pity.

Actually I thought this road cut count was as simple as could be. A regional connection exists between counties where there is a numbered state highway. Within a county there is a single connection between each locally connected fragment. In a macrochopped county there is a connection between counties and fragments where a regional connection exists (used for the second number). One then proceeds to count the cuts as I did above (number after the slash).

Is there an instance in my description above where this didn't work?

[muon2]

By my metric there are either agreed subunits that take in every parcel or not.

A) If there are agreed subunits then the usual erosity rules apply to those subunits within a county and across county lines.

B) If there are no agreed subunits then chops are assesed for munis in the county. The pieces of each district become the subunits and erosity is assessed on those (as we do with simple chops). Since every parcel is in a district the district pieces can serve as subunits for erosity.

My analysis assumed no agreed subunits but agreed munis as in case B.

[muon2]

I understand all of the above, but I don't think it is responsive to my post. Of course, we are only talking only about macro chopped counties. I accept that the precinct nesting issue should not be the tail that wags the dog. It is just an indication of whether or not there are subunits that anybody cares about for election purposes. The issue is where there are no subunits, how necessary is it really to artificially generate them?  You say one reason is that you might end up with wide partisan swings. I reply that maybe that is not so bad, if it gets the SKEW down, provided the maps don't get too erose looking. You offered up a map that looked erose, but much of that is really due to the shape around the Newcastle area, with a highway squeezing by to keep the CD connected. I grant it looks kind of ugly however. I put up a map that was not so ugly, and also did not impact SKEW, that would seem to me to have fewer highway cuts. You assert that there are more. I don't understand how. I am not sure how road cuts are counted between subunits in macro chopped counties. I thought it was any road. Granted if there is one big swath of land in King without subunits it gets to be cumbersome to count every road, where the unincorporated subunit is chopped. The Cedar River however, happens to make it all manageable in this case it would seem, particularly if any pavement connections will do within a county.

Speaking about chops of subunits in macro chopped counties, I am thinking of allowing one chop without penalty of a subunit to get the SKEW down, subject of course to a road cut count, so it does not get too ugly. The same thing within a big city. It if has neighborhoods, allow one chop to get the SKEW down, subject to the erosity rules. You won't like that one either probably. And what do you do with cities that have no neighborhoods, like seemingly Tucson, that are usable? What about Phoenix? Just create some out of whole cloth? What I do is try to have straight lines preferably following highways. Generally, in cities without apparent usable neighborhoods my chops within cities are highly "artistic" and pleasing to the eye. I like it that way. Anyway, the point being, that if there are going to be subunits everywhere in counties subject to macrochops, generated somehow, the one bite hope rule might be a workaround to deal with SKEW issues. That might be the right compromise, the Golden Mean, to resolve this particular food fight. Dogs get one bite with a negligence rap, and maps similarly get one bite in this context.

The big question you raise, and it was one that we settled two years ago over MI, is should political measures be used as a filter for maps or for informational purposes only. Two years ago your feeling matched the consensus that it should not, so I provided those scores on submissions from train, jimrtex, you and I, but did not cut on them. We used them to see if other rules were gaming the system. Now you seem to revised your position, but it will need serious convincing for me that will include a complete revisit of our work in MI.

I'd like to put off the SKEW question here and focus on how to measure erosity in macrochopped counties with no agreed subunits. The erosity metric assumes established connections that can be broken, and that in turn assumes that every parcel is assigned to something that can be connected. We have no agreement on assignment for unincorporated parcels, so they have no connections, so there is no erosity.

As I look at this I would create a hybrid of munis and school districts extending out from their munis where munis are embedded. That would comport with the public sense of belonging that jimrtex favors and I think helps sell the concept, but maintains smaller munis as both you and I would use as natural divisions. My experience with county election boards is that they don't care much about the districts not under their purview unless compelled by state law. Hence munis are treated well, but school districts are not.

For the large cities I would do what I did with Detroit and the VA cities. I would look at each city web site to find their planning areas. They almost always have them. Those then become the subareas within the city.

[muon2]

You could create an erosity test by just counting the highway cuts, however defined, within the cut "jurisdiction," in this case being the unincorporated area. That seems quite logical to me. You don't count highway cuts at all in chopped jurisdictions? If you don't, then you can draw the lines anyway you want in the chopped jurisdiction it would seem. What if a school district takes in a city and territory outside it? Is the territory outside the city its own jurisdiction for your purposes?  

I am really not that hostile to creating such artificial jurisdictions, if something can be created that is workable. My fix that I think will work is my one chop rule. It is not only about erosity, and SKEW per se, which I think are very important, but also that map lines in this context will be a function of population accident if there are lines that happen to avoid any chops. That is a horrible result in this context - just horrible.

You raise the estoppel argument often with me. I don't feel estopped at all. If I have new insights, as I gain more experience and knowledge, I am going to change my mind, or finally form an opinion, or an informed opinion. In some cases, I really didn't understand some of the details, and certainly not all of the implications. This for me, will always be a work in progress, always, until I am satisfied that the best approach possible can be fashioned.

It's that "however defined" that is the crux here. My only constraint is that a macrochopped county have subunits that include every parcel. I assume that they will not be the same in every state, since potential county subdivisions vary so widely across the 50 states. For 25 of them we have the town/township model. Each of the others needs its own definition.

In WA I think precincts are too small and using whatever chop pieces emerge are too big (that's the reason for my King gerrymander - I think it should be disfavored on the EROSITY score). Let's stipulate that the munis are separate from each other in subunits. The question is how to group the remaining unincorporated parcels. This can be done by clustering them as psuedo munis, perhaps by school district. In some cases the pieces may be so small that it makes sense to aggregate them with the associated muni, but in other places they would not be.

I think the reason for my estoppel arguments comes from my science background. If I build a model that fits one set of data, I'm very interested in testing the model with new data. Important refinements to the model may result. However, if there is a significant change to the model I feel compelled to double back to my original data set and see what impact it would have. I cannot rely on it working on the new data alone. If the choice is between an old model that works for one set of data and a new model that works for a different set of data, my training is to stay with the established model until the new model is shown to fit the old data, too.

[muon2]

Car rides are good for thinking, but less so for drawing, so this took a while. Here is a rule based way to create subunits, applied to King. These are the rules I used:

1. Each incorporated municipality is in its own subunit.

2. Contiguous unincorporated areas in the same school district are in a single subunit. Precincts that overlap multiple districts are assigned to the district with the most voters in that precinct.

3. Incorporated municipalities entirely within an unincorporated subunit are merged.

4. Unincorporated subunits entirely within an incorporated municipality are merged.

5. Unincorporated subunits smaller than 0.5% of the quota are merged with an adjoining municipality in the same school district.

I ended up with 51 subunits shown below as a whole county and with detail on the western side. Colors are grouped by school district with darker shade for munis and lighter shades for unincorporated subunits. If this seems workable I can produce the connection map to use for erosity. I also have the populations of each of the subunits if they are of interest.

[muon2]

What is the purpose of rule number 5? Is this a case where the portion of an unincorporated area that is not within a municipality but is within the same school district is less than 0.5% of the quota?

Yes. There are disconnected fragments outside of munis that often are assembled into a precinct. They are small and pose connection problems. Given the small pop (microchop size) it is much easier to append them to something larger.  The munis already pick up pop from surrounded fragments so picking up these other isolated fragments is consistent.

[muon2]

I'm not sure I'm clear on the one bite rule. Is this for cases that are macrochops and governs the number of chopped subunits? If so, is this applicable in well-divided counties like in the Midwest? How does it function if there are 3 or more districts in a macrochopped county?

I think you misunderstood my reservation rule. Each separate reservation was its own entity, much like my split of King unincorporated areas by school district.

Keep in mind (and it may already be so) that inequality, chop and erosity are used to form the Pareto set. Skew (and polarization) comes in afterward, applied to those plans in the Pareto set.

[muon2]

Let's set aside our disagreements about chop penalties and the overall scoring metric for the time being and return to the purpose of this thread which is defining the EROSITY score. It is one of the axes of the Pareto diagram, and isn't directly impacted by how one scores chops, skew, or the rest.

Here is my working definition that I posted earlier in the thread.

A political unit can be represented by a node that is the political center of that unit. For a county the node is the county office where the elected officials meet. For a city or town the node is the city or town hall. For a precinct the node is the polling place. Units are connected based on the path that connects their nodes.

Two units are locally connected if there is a continuous path of public roads that allow one to travel between the two nodes without entering any other unit. Local connections can include seasonal public roads. A local connection path can be traced over water without a bridge if there is a publicly available ferry that provides part of the connection. Units smaller than a county must be locally connected within a district.

Two counties are regionally connected if there is a continuous path of numbered state or federal highways that allow one to travel between two nodes without entering any other county. If a node is not on a numbered highway, then the connection is measured from the point of the nearest numbered highway to the node. The path may only use roads that are generally available all year. Regularly scheduled year-round ferry service may be included in the path of a regional connection. Counties must be regionally connected to be connected, except that counties within a cluster are connected if they are locally connected.

There is often more than one possible path to connect to nodes. For both local and regional connections the connection between two units is considered to be based on the path that takes the shortest time as determined by generally available mapping software.

It is on the definition of regionally connected that there is still disagreement on the corner cut issue. Is the rest is agreed?

Now let me put up my working definitions of the impact of chops on connections.

A chop occurs when a geographic unit is divided between two districts. For congressional districts, chops less than 5% of the quota are simple chops. Those chops in excess of 5% are macrochops.

For simple chops each connection from the original unit to adjacent nodes is assigned to one of the chopped parts. The part that has the border containing the connection path is assigned the connection. Note that connections to adjacent nodes cannot be lost by chopping a unit. Within the chopped unit the chopped parts are connected to each other if they are locally connected.


The best example is the one I used for King earlier in this thread. The first number before the slash for each district followed the rule above. A modification to the above would require that each chopped part have regional connections to adjacent county nodes that could be cut. That is what went into the second number after the slash in the King example.

The rule is consistent with our methodology in the MI exercise. Note that the only increase in erosity compared to keeping the county whole occurs from the severed internal link, and can reduce erosity as we saw with the recent NC plans.

The modified rule tends to increase erosity for simple chops, and the thinking two years ago was that the chop penalty was sufficient, without adding additional penalties for erosity.

For macrochops each unit is replaced by its complete set of subunits. Subunits are connected within a county if they are locally connected. Subunits are connected across a county line if they are regionally connected.

EROSITY is the sum of all connections severed by the boundaries between districts.

I think that the concern about the type of connections in Phoenix is solved by using the local connection requirement. The type of road doesn't matter in that case.

The principle issue here I believe is what constitutes the subunits of a county in a state with no township level government, and what constitutes subunits of a large city that will typically be chopped. Both the King county and Phoenix discussions go to that issue. We had similar discussion for Detroit in the MI exercise.

[muon2]

I agree with the use of the "internal villages" of Phoenix for subunits. I used them myself in my post on Torie's AZ thread back in March.

Anyway here's a version of AZ that only keeps one HVAP-majority CD (56.8%). There is only one extra cover in the Phoenix UCC and no pack penalties. I had a choice between an extra chop into Pinal or a chop into one of the large suburbs, so I went with the Pinal chop. It turns out that Phoenix has 15 recognized "villages" within the city limits. My CD 7 chops none of those to the extent that precincts allow, and only one of the 15 is chopped between CD 8 and 9. I could have avoided that chop but the erosity would suffer.

[muon2]

Those are some useful suggestions, jimrtex.

The one I'd quibble most with is associating non-small cities with school districts. One issue is it would lead to fewer and substantially larger subunits. The second issue is that many of the incorporated cities did so to have a clear identity apart from the school district. An example of this is Lake Forest Park which incorporated in 1961 from unincorporated Shoreline. Shoreline only incorporated the western part of the school district in 1995.

The small city merger raises a parallel question to one we faced in the Detroit metro. In Oakland county there were a number of small communities around Royal Oak. This allowed a plan to avoid muni chops but at the expense of erosity. If states like WA merged them away, they lose the type of trade off available in MI.

[muon2]

Erosity is based on network theory. The map is reduced to a network of nodes and links. Cut links measure erosity.

Sometimes a node needs to be split in the network. In the simplest case the node becomes two nodes and each link to the original is assigned to one of the two new nodes, and a link is placed between the two new nodes. That's a simple chop. This only involves state highways if state highways were used to define the original links before the split, as they would in the case of counties. A chop of a subunit only involves local connections.

Certain splits are significant enough that the original node is replaced by a whole new network. That new network has nodes that we call the subunits. There are links both between the new nodes and from the new nodes to other nodes that were originally connected to the original node. The connection rules are applied based on whether the nodes are in the same county or in different counties. The result is a new network that can be analyzed for cuts. I used this approach for Marion and a good example is the Mecklenburg map I posted earlier in the thread (pink links are non-connections and yellow lines are local connections that wouldn't count across county lines).



It gets more complicated when macrochopped counties are next to each other. To illustrate let me use the Detroit UCC map that was the basis for our erosity scoring back in Feb/Mar 2015. Each of the three counties was replaced by all of their subunits. Subunits in a county were connected if they were locally connected (blue lines). Subunits across county lines were connected if they were regionally connected (red lines). The process remains that once a macrochop occurs the subunits are analyzed for connections with no knowledge of the connections defined between the original counties.



Anytime a unit or subunit has a large enough chop it becomes a macrochop. At that point the original node is replaced by a new network of nodes. That would apply to Phoenix as it did to Detroit earlier this year. In Detroit we used the 10 city-defined planning regions as subunits, and they are drawn in the multicounty map above based on the detail from the following map.



The precincts don't nest in the planning regions so they have to be assigned based on the region most of the population resides. There isn't a city hall associated with the planning regions, so the node for each was based on the largest population precinct in each. That's why I mention precinct nodes.

[muon2]

Yes, I think having a size requirement for municipalities is a bad idea, except for when it comes down to having subunits within a municipality. My one bite rule might help here. The downside of small entities, is that the roll of the population dice becomes more salient perhaps in drawing the lines, and might make for more erose maps. The upside of small units is that it will help to avoid chops. The one bite rule helps hopefully to come up with a reasonable balance, and reduce the import of the dice roll factor. By the way, Michigan law embraces a one bite rule. It's just that in Michigan, the idea was to maximize SKEW, and it was unconstrained by highway cut counts. Thus that magnificent bridge chop to Pontiac.  Oh dear, do we have a bridge chop issue now for subunits? Probably the same preference rule should be in play - perhaps. The Pontiac syndrome will never work anyway, given highway cut counts, even if SKEW weren't a factor. It is grand that Section 5 is dead. Some of the mess created by the VRA is now gone, with retrogression in the dumpster, and the test with what is performing now the law of the land.

I assume that the reason for assigning precincts is where they are non nested, which hopefully would become a moot point. I know that I assign precincts based on where most of the population is, based on zooming down, and trying to discern where the bulk of the residential units are. Sometimes it is hard to tell, particularly if it is a matter of deciding whether buildings are apartment units or commercial buildings. Maybe defining precinct nodes is done to deal with non nested precincts. Non nested precincts are a bane. They should be made illegal.

Actually the history of the the one bite rule in MI was to provide for exact population equality when used initially by a neutral master (Apol). It became a tool for achieving political outcomes once it was handed to legislative mappers. If MI had a chop count rule and allowed population deviation without the one bite rule their ability to gerrymander would have been seriously hampered.

Did my long exposition on macrochop connection make sense, and are there any points of dispute there?

[muon2]

I agree with the use of the "internal villages" of Phoenix for subunits. I used them myself in my post on Torie's AZ thread back in March.

Anyway here's a version of AZ that only keeps one HVAP-majority CD (56.8%). There is only one extra cover in the Phoenix UCC and no pack penalties. I had a choice between an extra chop into Pinal or a chop into one of the large suburbs, so I went with the Pinal chop. It turns out that Phoenix has 15 recognized "villages" within the city limits. My CD 7 chops none of those to the extent that precincts allow, and only one of the 15 is chopped between CD 8 and 9. I could have avoided that chop but the erosity would suffer.

Yes, and you made AZ-09 a Pub CD by having AZ-08 chop into Phoenix where it did, presumably because choosing to chop in and absorb the Deer Valley neighborhood avoided a neighborhood chop. Congratulations.  Wait a minute, you chopped Deer Valley it seems. Which raises the question of why AZ-08 did not chop in to take in the northern neighborhoods, so that AZ-09 could take in North Mountain? Did it involve an extra highway cut, or was that before the sensitivity to SKEW arose?

As I wrote at the time there is one neighborhood chop between 8 and 9 that could have been avoided at the cost of erosity. The erosity is based on local connections only since these are intra-county. The plan only seeks to get to the Pareto frontier, so no political data was considered in drawing the lines.

[muon2]

OK, but could a plan that did not Pub up AZ-09 be drawn that reached the pareto optimal frontier is the question. The issue is whether by playing with the lines within Phoenix, in a way that does not look too ugly, we could get a 6-3 map, rather than a 7-2 map. It's a darn important question. This is where the rubber meets the road as to whether this whole scheme will ever fly, when all of its implications are understood, by the Democrats in particular. And it's darn important to try to get the party on the short end of the SKEW stick more seats in such states, consistent with good maps, particularly where the SKEW is very high, and a 7-2 map has a really high SKEW, just like a 9-0 map in Massachusetts has a really high SKEW. That is simply good government. We don't want a Pub party totally dominated by the South, and a Dem party totally dominated by areas outside fly over country. That's an increasingly serious problem that we have. So we need, to the extent that we can, consistent with good maps, to try to get there. The Pubs will still have the SKEW advantage overall. It's a pigs get fat, but hogs get slaughtered, situation.

If it is not possible to draw an AZ-09 that affects SKEW in a downward direction, without the map getting too choppy or erose, then so be it. Then it becomes defensible. We don't "gerrymander" to get SKEW down. We just need to be careful in how we define what is a gerrymander. Very careful.

That's why I'd like to separate the erosity question for now. Let's pin that down to define the score on that axis. Then we can pin down the chop score axis. Then we can take individual states and see what plans make the Pareto cut, and whether plans that should be considered politically were excluded. If we then see that some good plans are excluded, we can revisit the scoring that knocked them out.

For example the natural place to start would be to go through a thread like MI, where we had agreement on the measures. We can look at the political values of the plans on the frontier and see if the results are defensible. If we want to start with AZ or WA we first have to define how the axes are scored in those states as we did in MI.

[muon2]

Well at the moment we are working on AZ and WA. What more do we need to work out?  I am proposing we work out my one bite rule, and try to get this road cut thing nailed down. I accept dumping everything into subdistricts, and that the nesting tail should not be wagging the dog. So we are making progress! And we now have a nice little list of the open issues, which seem actually to be growing. Perhaps one day over the rainbow they might start shrinking again. Miracles happen.

And we need to see about drawing a second Dem district in Phoenix per the 2010 census, and whether these rules knock out a nice looking map that would have such a district, as opposed to something that deserves to die because it's butt ugly, and/or chop chubby (the latter being more about not letting some unpleasant genie out of the bottle, that might wreck havoc elsewhere). Could we help Mathis out here in a more defensible way in Phoenix?

I didn't think the one bite rule affects the erosity. Isn't the one bite just a subunit chop that doesn't add to the chop score?

Working out subunit rules for these western states isn't easy, and each state may be somewhat different. Applying them is time consuming. Precincts in WA and AZ got adjusted to muni lines after the remap (Maricopa last did it in early 2012), so in 2010 some amount of the non-nesting is due to accumulated annexations before 2010. Let's just pick one western state to see how it works, then take up the other.

[muon2]

I would move forward with WA, since I have the advantage of King completed (maybe), and we have a number of watchers from WA who might weight in. That of course assumes the rules I laid out for subunits are good to go, with the addition of jimrtex rule 0.

jimrtex suggested some other mergers as well - smallish cities and other unincorporated areas beyond the 0.5% limit I used. Maybe the 0.5% should be cutoff for incorporated cities?

Population requires King, Pierce and Snohomish be given subunits. Yakima and Kitsap are macrochopped in my map, so they need to be done as well. Any others?

That will allow connection plans to be assembled. Perhaps the corner cut provisions will move towards resolution in this as well.

[muon2]

I had some questions I laid out about the subunit rules that I set out, mostly out of confusion. I don't know what the Jimrtex zero rule is. Where to put bodies of water? Who cares? We don't want to generate a chop over areas with no population anyway. I am skeptical about erasing small cities. There had better be a good reason for that. Otherwise, they might feel picked upon. And it does give more guidance as to where precise lines should be drawn. I grant that it does not involve skew issues.

Any county really that is subject to a macrochop in end should be mapped out, not what our maps happen to chop up. Granted, Spokane is not subject to chop, and never will be, at least for CD maps. Clarke county might be subject to macrochop. I still want to know when city neighborhoods need to be mapped out. When they are subject to macrochop?

The jimrtex rule 0 was that municipalities and school districts are cut at the county line. I thought it went without saying since this was about county subunits, but since everyone want more clarity, I can include it.

Any county with a population over 10% of the quota could get macrochopped. In WA that includes Benton, Chelan, Clallam, Clark, Cowlitz, Franklin, Grant, Grays Harbor, Island, King, Kitsap, Lewis, Pierce, Skagit, Snohomish, Spokane, Thurston, Whatcom, Yakima. I'll set up a thread for all WA related tests of the rules. The subunits will go there as needed.

Any city that gets macrochopped gets subunits. There are 13 cities big enough to macrochop.

As I understand the one bite rule, it exempts one chop of a subunit cut between two districts from scoring as a chop. The chopped subunit still creates connections as appropriate that can contribute to erosity.

[muon2]

I had some questions I laid out about the subunit rules that I set out, mostly out of confusion. I don't know what the Jimrtex zero rule is. Where to put bodies of water? Who cares? We don't want to generate a chop over areas with no population anyway. I am skeptical about erasing small cities. There had better be a good reason for that. Otherwise, they might feel picked upon. And it does give more guidance as to where precise lines should be drawn. I grant that it does not involve skew issues.

Any county really that is subject to a macrochop in end should be mapped out, not what our maps happen to chop up. Granted, Spokane is not subject to chop, and never will be, at least for CD maps. Clarke county might be subject to macrochop. I still want to know when city neighborhoods need to be mapped out. When they are subject to macrochop?

The jimrtex rule 0 was that municipalities and school districts are cut at the county line. I thought it went without saying since this was about county subunits, but since everyone want more clarity, I can include it.

Any county with a population over 10% of the quota could get macrochopped. In WA that includes Benton, Chelan, Clallam, Clark, Cowlitz, Franklin, Grant, Grays Harbor, Island, King, Kitsap, Lewis, Pierce, Skagit, Snohomish, Spokane, Thurston, Whatcom, Yakima. I'll set up a thread for all WA related tests of the rules. The subunits will go there as needed.

Any city that gets macrochopped gets subunits. There are 13 cities big enough to macrochop.

As I understand the one bite rule, it exempts one chop of a subunit cut between two districts from scoring as a chop. The chopped subunit still creates connections as appropriate that can contribute to erosity.

I don't think I got the response I was looking for. My query was not about road cuts, but about chop count and road connections.

If there is a chop into a county and then a chop of a subunit in the county, does it count as only one chop under the one bit rule?

If there is a chop into a county, but no subunit chop, does it still count as only one chop under the one bite rule?

If there is a chop into a county and then a chop of a subunit in the county, does it create a local connection between the pieces of the subunit under the one bite rule?

If the above questions are answered yes, then I would be substantially more comfortable about this as long as there was some size limit to the rule. Personally, I would cap the rule at bites that do not exceed 0.5% of the quota. For me that allows one to deal with small excursions from the geographic measures to accommodate the other measures, but keeps the focus on those primary measures. I don't like the idea that the rule can be used to separate a city like Glendale AZ into a Dem part and a Pub part without penalty. That's the essence of political gerrymandering.

[muon2]

Interesting questions. I was focused more about chops that are created by these "artificial" subunits, which are less salable out there. That is a very substantial concern of mine. So there is the issue of whether to create distinctions between real towns and cities, and these constructs, particularly cities I guess. I am not sure what to do about that. It is more an empirical issue. In all events, a 0.5% limitation is way too small. That is only 3.500 people or so and trivial. That is not going to do much good at all. I would think a limitation of 5%, or 35,000 people, is more appropriate. Tentatively, I would tend to think that the one bite rule will not apply to cities, but would to everything else, with the 5% limitation. That way, we do not get disparate results between those states that have little towns here, there and everywhere (NY has them taking in all real estate, as does Michigan), as opposed to states that do not.

At 5% it becomes a macrochop of the subunit, so you are suggesting (I think) that any simple chop of an unincorporated subunit, or neighborhood of a macrochopped city is subject to the one bite rule. Presumably that means townships in the Midwest, too. If so, there would seem to be no incentive to keep them intact.

[muon2]

City planning areas usually work well. We used them in Detroit, and would think they would work in Milwaukee too. Detroit also had smaller neighborhoods that were bypassed in favor of planning areas.