The Missouri Miracle – and a Celebration of the Muon2 Redistricting Rules

[muon2]

I agree, the MO map looks quite nice. Keep those RRH folks in line.

The key to using inequality is to get away from the really de minimis variations of say a range of 3036 beating a plan with a range of 3241. Instead inequality is measured on a scale that is tuned to the expected number of chops so they can be compared apples to apples. Basically each chop should lower the inequality by 1. Chops and inequality can be used either one or the other, or as we saw in our MI exercise the best results came from using a sum of the two on one axis. Erosity then forms the other axis for the Pareto test.

With my current definition, a bridge fragment that includes the regional connection between the separated counties has no penalty at all. If the bridge fragment has a connection that isn't the primary regional connection then it acts like two counties only connected locally, which gets an erosity penalty for extra components. If the bridge fragment is a macrochop then the calculation of erosity is based on the subunits of the macrochop and not the overall bridge fragment, just as any other macrochop would be measured.

Speaking of connections - it's not clear if your Jackson fragment has one to Clay. At best it looks like the MO-291 bridge is in the district, but I can't tell if it includes the local roads to get over to  the eastern part where the node is. Even if it does, 291 isn't the regional connection between Jackson and Clay, so they would count as only locally connected. That makes the Jackson fragment a separate component and adds one to erosity.

[muon2]

Here's the relevant example on the Jackson fragment and its relationship to Clay. The situation is like the Dawes to the West Agnew fragment which I've highlighted in the quote.

The first special rule for connections is for fragments. This follows what was worked out earlier in the thread.

Definition: Fragment. A fragment is the contiguous part of a unit entirely within a district formed by a chop of that unit. Fragments are artifacts of a specific redistricting plan and need not correspond to a recognized political unit. The node of the fragment containing the node of the chopped unit is that same node. For a fragment that does not contain the node of the whole political unit, the node is that of the most populous subunit in the fragment.

Item E2: Fragments trace paths to their nodes as if they were part of the original unit. A connection to the node of a fragment exists if the connecting path to the unit with the fragment enters the unit in that fragment. Fragments within the same unit are locally connected if their nodes are locally connected.

This example is based on the the previous unchopped one. The 5 geographic units are Agnew, Burr, Calhoun, Dawes and Elbridge, labeled A through E. The nodes are indicated with stars and the roads are shown with heavy lines.



The shaded area represents a district that chops unit Agnew.

The East Agnew fragment has a node from the original whole Agnew. The West Agnew fragment has a newly created node shown as a hollow star that will be used as a placeholder for mapping.

The path from Agnew (before the chop) to Calhoun without a chop enters Agnew in the West Agnew fragment, so there is a link from West Agnew to Calhoun.

The path from Agnew to Elbridge enters Agnew in the East Agnew fragment, so there is a link from East Agnew to Elbridge.

The primary path from Agnew to Dawes enters in East Agnew, so there is a link from East Agnew to Dawes. A secondary path from Agnew to Dawes enters in West Agnew, but does not form a link.

The primary path from Agnew to Burr enters in East Agnew, so there is a link from East Agnew to Burr. A secondary path from Agnew to Burr enters in West Agnew, but does not form a link.

There is a path between West Agnew and East Agnew that forms a local connection, so there is a link between those fragments.

The equivalent graph colors the nodes of the two districts in different colors. The dashed lines represent secondary paths between nodes that do not count as links. The red lines indicate links and secondary paths that link nodes in different districts.



nb. As noted in the example the dashed lines represent real local connections, but not links. Links are based on the shortest connecting path. That's important in cases where a path of local connections is required, but no link is available. This situation will be addressed further in the special rule for isolated fragments and in the definition for components.

[muon2]

"With my current definition, a bridge fragment that includes the regional connection between the separated counties has no penalty at all. If the bridge fragment has a connection that isn't the primary regional connection then it acts like two counties only connected locally, which gets an erosity penalty for extra components. If the bridge fragment is a macrochop then the calculation of erosity is based on the subunits of the macrochop and not the overall bridge fragment, just as any other macrochop would be measured."

Does this have something to do with nick cuts (the no penalty variation)?  If that is the case, then the rule makes sense. Bridge chops will generally not pay, including what you used to call not a bridge chop merely because the county on the other side of the bridge chop was not entirely within the CD. I hated that.

It depends on the nature of the nick cut - basically is it a pure nick cut or does it involve other connections. I give a lengthy example in the muon rules thread.

[muon2]

Should Kansas City be treated as a county since it has its own election board, or alternatively should it be treated as if it is entirely in Jackson County?

I don't think so. I don't know about MO, but in many states where cities can span multiple counties statute makes it clear that the portion in each county is treated separately. Aurora IL is in four counties and has its own electoral board for three of those counties. Even so, precincts cannot span county lines. It makes the most sense to treat district lines the same way.

[muon2]

Should Kansas City be treated as a county since it has its own election board, or alternatively should it be treated as if it is entirely in Jackson County?

I don't think so. I don't know about MO, but in many states where cities can span multiple counties statute makes it clear that the portion in each county is treated separately. Aurora IL is in four counties and has its own electoral board for three of those counties. Even so, precincts cannot span county lines. It makes the most sense to treat district lines the same way.

Can precinct boundaries span city lines?

If the city does not constitute an election jurisdiction, like a township, then the precinct lines can cross muni lines. They do in my township.

[muon2]

Should Kansas City be treated as a county since it has its own election board, or alternatively should it be treated as if it is entirely in Jackson County?

I don't think so. I don't know about MO, but in many states where cities can span multiple counties statute makes it clear that the portion in each county is treated separately. Aurora IL is in four counties and has its own electoral board for three of those counties. Even so, precincts cannot span county lines. It makes the most sense to treat district lines the same way.

Can precinct boundaries span city lines?

If the city does not constitute an election jurisdiction, like a township, then the precinct lines can cross muni lines. They do in my township.

I think that the district entirely in the UCC should include all of Kansas City.

If an objective set of rules prevents this, my subjective opinion is that there is a problem with objective set of rules.

Geographically for chops to make sense there should be a clear hierarchy of units, each of which spans the entire space of the preceding unit. For example in WI we are using

UCCs (as applicable)
Counties
Cities/Villages/Townships
Wards/VTDs

There are cities and villages that cross county lines, but WI says they aggregate their votes by parts in separate counties. For electoral and redistricting purposes a city in two counties acts as two separate cities, each wholly in a county.

[muon2]

"each of which spans the entire space of the preceding unit"

Since that cannot mean "nested within," just what does it mean?

Span here means to completely cover the space with its elements, and I'm using it to also mean without overlap. For example the set of cities, villages, and towns in a WI county covers all the area in that county without any overlaps. Similarly the set of wards in a city WI covers all the area of that city without overlap.

[muon2]

OK, well that does not help where there are overlaps, as with KC, or Indian Reservations, so it is not a universal principle.

Within a MO county there are no overlaps between cities. That's the point of a hierarchy, I don't look at objects outside of a county in dealing with chops. In WA we used municipalities and school districts outside of munis, and together they formed sets that spanned each county. If reservations need a special status the best choice within the system is to create a county cluster that includes the reservation and use the UCC rules with it. It's not unlike the Black Belt cluster we looked at in analyzing maps of AL.

[muon2]

OK, well that does not help where there are overlaps, as with KC, or Indian Reservations, so it is not a universal principle.

Within a MO county there are no overlaps between cities. That's the point of a hierarchy, I don't look at objects outside of a county in dealing with chops. In WA we used municipalities and school districts outside of munis, and together they formed sets that spanned each county. If reservations need a special status the best choice within the system is to create a county cluster that includes the reservation and use the UCC rules with it. It's not unlike the Black Belt cluster we looked at in analyzing maps of AL.

Well we have been around this before, but that does not reward a map that both avoids a county and a reservation chop. In your system, you would ignore the county chop, if there were one. Ditto for a map that manages to both keep KC whole, and Jackson County whole, as opposed to treating a map that chops KC as just as good as one that does not, all other things being equal. It is another example of elegance over, well, what makes sense.

I would treat all chops equal. If there are two small counties that have a reservation across the border and they were a CC, then splitting the reservation along the county line would be a chop. keeping the reservation together, but splitting one of the counties would also be a chop. Neither is favored.

I think a Jackson +KC would be a mess given the shape of KC up north. The more likely split is to put all of the UCC plus the Jackson part of KC in a district, then attach the rest of Jackson to something else. That's not a penalized bridge chop in my current formulation.

[muon2]

Should Kansas City be treated as a county since it has its own election board, or alternatively should it be treated as if it is entirely in Jackson County?

I don't think so. I don't know about MO, but in many states where cities can span multiple counties statute makes it clear that the portion in each county is treated separately. Aurora IL is in four counties and has its own electoral board for three of those counties. Even so, precincts cannot span county lines. It makes the most sense to treat district lines the same way.

Can precinct boundaries span city lines?

If the city does not constitute an election jurisdiction, like a township, then the precinct lines can cross muni lines. They do in my township.

I think that the district entirely in the UCC should include all of Kansas City.

If an objective set of rules prevents this, my subjective opinion is that there is a problem with objective set of rules.

Geographically for chops to make sense there should be a clear hierarchy of units, each of which spans the entire space of the preceding unit. For example in WI we are using

UCCs (as applicable)
Counties
Cities/Villages/Townships
Wards/VTDs

There are cities and villages that cross county lines, but WI says they aggregate their votes by parts in separate counties. For electoral and redistricting purposes a city in two counties acts as two separate cities, each wholly in a county.

M.R.S. 999.999 Redistricting Counties

Before December 31 in the year ending in 0, the legislative body of each municipality that encompasses territory in more than one county may designate that for redistricting purposes, the municipality is to be treated as lying entirely in the county which contains the largest share of the population at the previous census. If the legislative body does not make such designation, the parts of the municipality that lie in different counties shall be treated as separate municipalities for redistricting purposes.

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Not that Wards/VTDs should not be used. But larger cities may/must designate neighborhoods. The use of wards in Ohio was really a mess.

For the purposes of our WI exercise on the other thread, do we know which munis passed such a resolution? Do we know to what extent the WI leg followed those resolutions? My fear is that since what you quote is a statute, if the remap is also by statute then the leg can overrule the munis.