Using Urban County Clusters To Guide Redistricting

[jimrtex]

Moderator's note: The discussion about LA and VRA requirements have been split off into its own thread (12/8/13).


The following maps illustrate how urban county clusters could be used in the redistricting process.

An Urban County Cluster is a group of counties from a Metropolitan Statistical Area which have 25% or more of their population in Urbanized Areas (urbanized areas are urban areas with a population of 50,000 or more).  So urban county clusters are characterized by significant levels of population concentration and significant commuting ties, which form the basis for defining metropolitan statistical areas.

There are three urban county clusters in Michigan:

Detroit: Wayne, Oakland, Macomb, Livingston, and St. Clair.   This is the entire Detroit MSA, with the exception of Lapeer, which has little population in urbanized areas, and is the most peripheral county.  Genesee, Washtenaw, and Monroe are not in the Detroit MSA, as Flint, Ann Arbor, and Monroe plus Toledo, provide an alternative focus for employment so a smaller share of their population commutes towards Detroit.

Grand Rapids: Kent and Ottawa counties.   Barry and Montcalm are also in the MSA, but do not contain portions of urbanized areas.

Lansing: Ingham, Eaton, and Clinton.  This is the entire Lansing MSA.

There are other single-county clusters, including Kalamazoo (Kalamazoo), Battle Creek (Calhoun), Muskegon (Muskegon), Ann Arbor (Washtenaw), Jackson (Jackson), Monroe (Monroe), Flint (Genesee), Saginaw (Saginaw), Bay City (Bay), Midland (Midland), and Niles-Benton Harbor (Berrien).  For redistricting purposes, these are treated no differently than other counties.



An Apportionment Region is a group of contiguous counties that has a population approximately equivalent to an integer number of congressional districts (for Michigan in 2010, 705,974 persons).  Ideally an apportionment region would have a population equivalent to one congressional district within an error of 0.5% (one-half of one percent), or  (702,444 to 709,504).  Such a region may directly form a congressional district comprised of whole counties, within acceptable levels of population deviation.

Apportionment regions with somewhat larger errors may be converted to congressional districts with relatively small shifts of a portion of one county.  Apportionment regions of higher magnitude will require significant divisions of counties.  Of course, some such division is unavoidable in Michigan, since Wayne, Oakland, and Macomb all have populations greater than that of one congressional district.

In the First Round, the goal is to create the most apportionment regions, which will in turn tend to create more regions that can form, with possible minor adjustments, a single district.

To qualify, an apportionment region must have an error of less than 5% of the ideal congressional district population.   That is an apportionment region with a population approximately equivalent to four districts, must have a population in the range 3.95 to 4.05, rather than 3.80 to 4.20.

An urban county cluster must be contained within a single apportionment region, unless the entirety of one or more apportionment regions may be created within the urban county cluster.  In such a case, the remaining counties, if any, of the urban county cluster must be contained in a single apportionment region.

More than one urban county cluster may be contained within an apportionment region.  However, because of the population of the urban county clusters, such an apportionment region may be rather populous.

While an apportionment region may have a deviation as much as 5%, closer is better, and plans that have unnecessarily large deviations may be excluded from consideration.

The length of the boundaries between apportionment regions is also a consideration.  Highly convoluted, or elongated regions are less compact.  The length of a boundary between two counties is considered to be the direct distance between the end points of that border.  



Portions of the counties within the Great Lakes and Lake St.Clair are not considered as forming boundaries or adjacency.  The only way (for a district) to cross from the Upper Peninsula to the Lower Peninsula is over the Mackinac Bridge.  For purposes of contiguity, both Emmet and Cheboygan counties are considered to be adjacent with Mackinac County, with a zero length border.

Point and near-point connections may not be used to establish contiguity.  A near-point connection is one where the length of the border is less than 10% of the square root of the area of the smaller county, excluding any territory within the Great Lakes.  In particular Gratiot and Shiawassee, and Livingston and Jackson may not be placed in the same apportionment region, unless other counties provide connectivity.  If the border between these counties coincides with boundary between apportionment regions, its length is included in the total length (in both instances, the connection is less than one mile).

[muon2]

The following maps illustrate how urban county clusters could be used in the redistricting process.

An Urban County Cluster is a group of counties from a Metropolitan Statistical Area which have 25% or more of their population in Urbanized Areas (urbanized areas are urban areas with a population of 50,000 or more).  So urban county clusters are characterized by significant levels of population concentration and significant commuting ties, which form the basis for defining metropolitan statistical areas.

There are three urban county clusters in Michigan:

Detroit: Wayne, Oakland, Macomb, Livingston, and St. Clair.   This is the entire Detroit MSA, with the exception of Lapeer, which has little population in urbanized areas, and is the most peripheral county.  Genesee, Washtenaw, and Monroe are not in the Detroit MSA, as Flint, Ann Arbor, and Monroe plus Toledo, provide an alternative focus for employment so a smaller share of their population commutes towards Detroit.

Grand Rapids: Kent and Ottawa counties.   Barry and Montcalm are also in the MSA, but do not contain portions of urbanized areas.

Lansing: Ingham, Eaton, and Clinton.  This is the entire Lansing MSA.

There are other single-county clusters, including Kalamazoo (Kalamazoo), Battle Creek (Calhoun), Muskegon (Muskegon), Ann Arbor (Washtenaw), Jackson (Jackson), Monroe (Monroe), Flint (Genesee), Saginaw (Saginaw), Bay City (Bay), Midland (Midland), and Niles-Benton Harbor (Berrien).  For redistricting purposes, these are treated no differently than other counties.

I think this makes a lot of sense as a definition. I like the restriction to counties within the MSA which avoids the whole merger question. For clarification, is the 25% rule based on some usage within the Census or is it arbitrary? I'd like to make the definition as defensible as possible. I know that the states vary on their definition of the threshold for urban vs rural. For example in PA the state average population density is used as the threshold for urban classification.

It appears that for the purposes of applying the 25% rule, the relationship of other urbanized areas within the county to the principal urbanized area is not a factor. Is there a table that clearly delineates the urbanized area population as opposed to the urban area population in the county? Again, I'd like to clearly source the definition, preferably from the Census web site.

[Torie]

Yes, I wonder how well this definition will work in other states, and where the data is.  And what and where do you look to know if more than 25% of the county is in "urbanized areas?"

[jimrtex]

The following maps illustrate how urban county clusters could be used in the redistricting process.

An Urban County Cluster is a group of counties from a Metropolitan Statistical Area which have 25% or more of their population in Urbanized Areas (urbanized areas are urban areas with a population of 50,000 or more).  So urban county clusters are characterized by significant levels of population concentration and significant commuting ties, which form the basis for defining metropolitan statistical areas.

There are three urban county clusters in Michigan:

Detroit: Wayne, Oakland, Macomb, Livingston, and St. Clair.   This is the entire Detroit MSA, with the exception of Lapeer, which has little population in urbanized areas, and is the most peripheral county.  Genesee, Washtenaw, and Monroe are not in the Detroit MSA, as Flint, Ann Arbor, and Monroe plus Toledo, provide an alternative focus for employment so a smaller share of their population commutes towards Detroit.

Grand Rapids: Kent and Ottawa counties.   Barry and Montcalm are also in the MSA, but do not contain portions of urbanized areas.

Lansing: Ingham, Eaton, and Clinton.  This is the entire Lansing MSA.

There are other single-county clusters, including Kalamazoo (Kalamazoo), Battle Creek (Calhoun), Muskegon (Muskegon), Ann Arbor (Washtenaw), Jackson (Jackson), Monroe (Monroe), Flint (Genesee), Saginaw (Saginaw), Bay City (Bay), Midland (Midland), and Niles-Benton Harbor (Berrien).  For redistricting purposes, these are treated no differently than other counties.

I think this makes a lot of sense as a definition. I like the restriction to counties within the MSA which avoids the whole merger question. For clarification, is the 25% rule based on some usage within the Census or is it arbitrary? I'd like to make the definition as defensible as possible. I know that the states vary on their definition of the threshold for urban vs rural. For example in PA the state average population density is used as the threshold for urban classification.

It appears that for the purposes of applying the 25% rule, the relationship of other urbanized areas within the county to the principal urbanized area is not a factor. Is there a table that clearly delineates the urbanized area population as opposed to the urban area population in the county? Again, I'd like to clearly source the definition, preferably from the Census web site.

The 25% threshold is somewhat arbitrary, but going down to 15% or up to 50% doesn't make a large difference.   There is a spreadsheet on the census bureau website that has the population of each urban area within each county, as well as the non-urban population of each county.  I used that file in combination with the census bureau definition of CBSA to make my calculation:

Using urban area population would have captured a great number of micropolitan areas, as well as fringe areas of metropolitan areas.   Atlanta MSA is up to 29 counties, and while the Atlanta  urbanized area does not reach that far, there are likely to be urban clusters in many of those counties.

There is a time lag problem.  Urban areas are not delineated until a few years after the census.  It might be possible to update populations of the 2000 urban areas, since there are equivalency files relating 2000 census blocks to 2010 census blocks.   It is the intent to update CBSA delineations based on commuting data from the 2011-2015 ACS, but the initial central counties will be those from the 2010 census.

These are the changes if the threshold was increased to 50% or reduced to 15%.

Alabama:
Daphne-Fairhope-Foley (x Baldwin County) 35%
Montgomery (trim Elmore) 34%

Arizona:
Lake Havasu City (x Mohave) 27%
Prescott (x Yavapai) 40%
Sierra Vista (x Coshise) 40%

Arkansas:
Little Rock (trim Lonoke) 45%
Fort Smith (trim Crawford) 48%

California:
Sacramento (trim El Dorado) 34%
Chico (x Butte) 45%

Connecticut:
Worcester, MA (trim Windham) 28%
Torrington (x Litchfield)

Florida:
Crestview-Fort Walton Beach-Destin, FL (add Walton 18%)

Georgia:
Atlanta (add Barrow) 17%
Atlanta (add Carroll) 19%
Atlanta (add Dawson) 20%
Atlanta (trim Walton) 33%
Chattanooga, TN (trim Walker) 45%
Chattanooga, TN (trim Murray) 30%
Macon (add Jones) 16%
Warner Robins (add Peach) 23%
Savannah (add Long) 19%
Savannah (trim Bryan) 31%

Hawaii:
Kahului-Wailuku-Lahaina (x Maui) 36%

Chicago (add Grundy) 24.6%
St.Louis, MO (trim Monroe) 29%
Carbondale (trim Jackson) 47%

Indiana:
Cincinnati, OH (add Dearborn) 20%
Indianapolis (trim Boone) 38%
Indianapolis (trim Morgan) 32%
Terre Haute (trim Clay) 39%

Iowa:
Des Moines (add Warren) 19%

Kansas:
St.Joseph, MO (trim Doniphan) 30%
Wichita (add Butler) 17%

Kentucky:
Clarksville, TN (trim Christian) 28%

Louisiana:
Baton Rouge (trim Iberville) 34%

Maine:
Portland (trim York) 34%
Bangor (x Penobscot) 40%

Maryland:
Balltimore (trim Queen Anne's) 26%
California-Lexington Park (x St.Mary's) 38%
Washington, DC (Calvert) 21%

Massachusetts:
Pittsfield (x Berkshire) 45%

Michigan:
Lansing (x Clinton) 36%
Lansing (x Eaton) 45%
South Bend, IN (add Cass) 17%

Minnesota:
Mankato (x Nicollet) 41%
Minneapolis-St.Paul (trim Sherburne) 29%
Minneapolis-St.Paul (trim Wright) 27%
Duluth (x St.Louis) 47%
Grand Forks, ND (trim Polk) 26%
La Crosse, WI (trim Houston) 28%

Mississippi:
Gulfport-Biloxi-Pascagoula (trim Hancock) 40%
Hattiesburg (trim Lamar) 49.6%

New Jersey:
Allentown, PA (trim Warren) 48%
New York-Newark, NY-NJ (trim Hunterdon) 46%
New York-Newark, NY-NJ (trim Sussex) 25%
Philadelphia, PA (trim Sussex) 40%

New Mexico:
Farmington (x San Juan) 41%

New York:
Kingston (x Ulster) 49%
Rochester (trim Ontario) 32%
Utica-Rome (x Oneida) 49%
Watertown (x Jamestown) 49.8%

North Carolina:
Asheville (x Haywood) 45%
Greensboro (add Randolph) 15%
Winston-Salem (add Davie) 17%
Winston-Salem (add Stokes) 24%
Myrtle Beach, SC (trim Brunswick) 37%
New Bern (x Craven) 49%
Raleigh (add Johnston) 22%
Rocky Mount (trim Edgecombe) 31%
Goldsboro (x Wayne) 49.8%

Ohio:
Cleveland (add Geauga) 22%
Columbus (trim Fairfield) 34%
Dayton (trim Miami) 46%
Toledo (trim Wood) 42%
Wheeling, WV (trim Belmont) 39%

Oklahoma:
Oklahoma City (trim Logan) 25%
Tulsa (trim Creek) 36%
Tulsa (add Rogers) 21%

Oregon:
Albany (x Linn) 40%
Salem (x Polk) 35%

Pennsylvania:
Bloomsburg (trim Montour) 46%
Gettysburg (x Adams) 31%
Johnstown (x Cambria) 43%
Allentown (trim Carbon) 27%
East Stroudsburg (x Monroe) 33%
Pittsburgh (trim Butler) 32%
Pittsburgh (trim Fayette) 47%
Chambersburg (x Franklin) 40%
Williamsport (x Lycoming) 48%
Youngstown, OH (trim Mercer) 33%

South Carolina:
Charlotte, NC (add Lancaster) 19%
Columbia (add Kershaw) 20%
Florence (add Darlington) 20%
Hilton Head Island-Bluffton-Beaufort, SC (x Beaufort) 43%

South Dakota:
Rapid City (add Meade) 24.9%
Sioux City, IA (trim Union) 39%
Sioux Falls (trim Lincoln) 49%

Tennessee:
Kingsport (trim Hawkins) 31%
Morristowm (add Jefferson) 20%
Sevierville (new Sevier) 17%
Nashville (add Robertson 20%)
Nashville (trim Wilson 37%)

Texas:
Corpus Christi (trim San Patricio) 26%
Dallas-Fort Worth (trim Johnson) 29%
Houston (trim Chambers ) 36%
Beaumont (trim Hardin) 39%
San Antonio (trim Comal) 49%

Utah:
Ogden (trim Box Elder) 49%

Virginia:
Staunton-Waynesboro (x Augusta + IC) 48%
Kingsport-Bristol-Bristol, TN-VA (add Scott) 18%
Kingsport-Bristol-Bristol, TN-VA (trim Washington + Bristol) 46%
Virginia Beach-Norfolk (add Gloucester) 24%
Washington, DC (trim Fauqier) 32%
Lynchburg (trim Amherst) 36%
Lynchburg (add Bedford) 18%
Lynchburg (trim Campbell) 32%
Richmond (trim Dinwiddie) 29%
Washington, DC (trim Prince George) 47%
Roanoke (trim Botetourt County) 36%

West Virginia:
Huntington (trim Wayne) 33%
Beckley (trim Fayette) 35%

Wisconsin:
Eau Claire (trim Chippewa) 43%

I don't see a compelling reason to drop down to 15%.  If the threshold were increased, I would change the definition to: county whose largest urban area is an urbanized area, and which has an urban population greater than 50%.  Many of the areas that would be disqualified based on a higher threshold, are because they have larger urban clusters that have not connected to the main urbanized area.

Ellis County, TX is at 56% because there is no Waxahachie UC, while Johnson County, TX is at 29% because Cleburne UC still exists.

[jimrtex]

EDIT: Corrections to maps.

Mixed up counties in Appleton and Oshkosh WI MSAs
Mixed up Lousville suburbs in Indiana (Floyd and Clark)
Showed Ottawa rather than Wood as part of Toledo, OH cluster.
Included Chatham, NC as part of Durham-Chapel Hill cluster.
Showed Goliad rather than Victoria, TX.
Omitted York, VA from Virginia Beach-Norfolk cluster.

No changes to SW and NW maps.

Yes, I wonder how well this definition will work in other states, and where the data is.  And what and where do you look to know if more than 25% of the county is in "urbanized areas?"

The lighter shaded areas (eg Washtenaw, Genesee, and Monroe) are separate Metripolitan Statistical Areas within a Consolidated Statistical Area (CSA).  The darker area is the "main" MSA for the CSA.  The original version used CSA, but these were too extensive (Allentown MSA is part of the New York CSA),

With the latest definition, the association between Ann Arbor, Flint, and Monroe and Detroit is simply to illustrate the evolution of definition.  The single county "clusters" are treated as ordinary counties.









Link to 2010 Urban Area to County Relationship File

Link to Core based statistical areas (CBSAs) and combined statistical areas (CSAs)

Some definitions:

Urban Area: Blob of continuous dense residential population, which are delineated (for the most part) without regard to political boundaries and have at least 2500 persons.  The Urban population lives in urban areas, the Rural population lives outside urban areas.

Urban Areas are classified as Urbanized Areas and Urban Clusters based on their population.  Urbanized Areas have a population of 50,000 or more.  Urbanized Areas have been defined since the mid-1900's to recognize suburban growth outside incorporated cities.  The concept of Urban Areas based on population density is new with the 2000 Census, though intended to provide continuity with the 1990 delineations.  Before 2000, the Rural population lived outside cities of 2500 persons.

Core Based Statistical Areas (CBSA) are groups of counties defined based on a core urban area and commuting patterns.  Metropolitan Statistical Areas are associated with Urbanized Areas, while Micropolitan Statistical Areas are associated with Urban Clusters.

Urban Areas with a population greater than 10,000 (that is, all Urbanized Areas and Urban Clusters with more than 10,000 persons) are potential cores of a CBSA.  A county is an initial central county if the urban area with the most population in the county, has greater than 10,000 persons total AND 5,000 persons or more, or 50% or more of the total county population.  Counties that share the same potential core, form an initial central county cluster.

Initial central county clusters are treated as a unit for determining outlying counties.  Outlying counties may be either initial central counties, or counties without a core area.  In the Detroit area, Wayne, Oakland, and Macomb form a central county cluster based on the Detroit Urbanized Area.  St. Clair, Lapeer, Genesee, Livingston, Washtenaw, and Monroe form separate initial county clusters (of one) based on Port Huron UA, Lapeer UC, Flint UA, South Lyon-Howell UA, Ann Arbor UA, and Monroe UA, respectively (Detroit UA extends into most of the counties but is not the dominant urban area).

St.Clair, Lapeer, and Livingston are converted to outlying counties of the Detroit-Warren-Dearborn Metropolitan Area based on commuting into the central counties of Oakland, Macomb, and Wayne (25% or more of workers resident in the outlying counties work in the central counties).   Genesee, Washtenaw, and Monroe remain independent MSA.

What my definition is intended to capture is counties with dense population, and strong commuting ties, but that happen to have a different urban core.

[muon2]

Yes, I wonder how well this definition will work in other states, and where the data is.  And what and where do you look to know if more than 25% of the county is in "urbanized areas?"

The lighter shaded areas (eg Washtenaw, Genesee, and Monroe) are separate Metripolitan Statistical Areas within a Consolidated Statistical Area (CSA).  The darker area is the "main" MSA for the CSA.  The original version used CSA, but these were too extensive (Allentown MSA is part of the New York CSA),

With the latest definition, the association between Ann Arbor, Flint, and Monroe and Detroit is simply to illustrate the evolution of definition.  The single county "clusters" are treated as ordinary counties.

I think I understand, and am still looking to put a firmer basis on the 25% rule. I assume this is the excel file you are referring to on this Census page.

In the meantime, I see Lucas and Ottawa, OH in the same cluster. However, they are not in the same MSA, but Wood is 41.97% UA in the above table so it looks like it should be with Lucas instead of Ottawa.

[Sbane]

I think using metropolitan areas in fair redistricting is a very good idea. Much better than minimizing erosity and splits.

[jimrtex]

Yes, I wonder how well this definition will work in other states, and where the data is.  And what and where do you look to know if more than 25% of the county is in "urbanized areas?"

The lighter shaded areas (eg Washtenaw, Genesee, and Monroe) are separate Metripolitan Statistical Areas within a Consolidated Statistical Area (CSA).  The darker area is the "main" MSA for the CSA.  The original version used CSA, but these were too extensive (Allentown MSA is part of the New York CSA),

With the latest definition, the association between Ann Arbor, Flint, and Monroe and Detroit is simply to illustrate the evolution of definition.  The single county "clusters" are treated as ordinary counties.

I think I understand, and am still looking to put a firmer basis on the 25% rule. I assume this is the excel file you are referring to on this Census page.

Comma delimited text file on this Census Page which also has the explanation of the file, as well as a similar file for relationships between urban areas and minor county divisions.   The latter file may be of use in New England, and possibly throughout the northeastern US.  For example, it might provide a better way to split Ottawa County between Muskegon and Grand Rapids.

Re 25%.

Typically, the percentage is up around 80% to 100%, but perhaps drops down to the 70% for smaller urbanized areas.  A lot depends on the size of the county.  El Dorado, CA fell be 50% because it has a substantial population around Lake Tahoe in addition to Sacramento.  The same is true for St.Louis County, MN where the Iron Range population is significant relative to that of Duluth.

The actual footprint of the urbanized area might be relatively small.  Lansing covers parts of 13 townships, in an area of the state where counties are 16 townships (4 x 4), 5 in Ingham, 3 in Eaton, 4 in Clinton, and 1 in Shiawassee.  In cases like that, the percentage of the county population might be somewhat low, because there is substantial area for smaller towns and urban fringe - areas where the residents commute but otherwise live in a rural setting.   20 ppm is probably a high number for purely agricultural area (4 largish families with 160 acres each).   But you could easily get to 200 ppm without any real crowding or need for streets.

The Lansing UA portion of Clinton County has 36% of the population in the county, in 5% of the area.  The density of the Lansing UA is 1018 ppm; of St.Johns UC is 1992 ppm.  And for the rural area it is 74 ppm.  It is denser than it would be without Lansing.

The Census Bureau definition of central county is not particularly helpful, since it appears to be intended for use with urban clusters and micropolitan areas.  It only requires 5,000 persons from the UC to be in the county.  But that is between 10% and 50% of the UC population.  But 5,000 persons is at most 10% of an urbanized area.

In the meantime, I see Lucas and Ottawa, OH in the same cluster. However, they are not in the same MSA, but Wood is 41.97% UA in the above table so it looks like it should be with Lucas instead of Ottawa.

It should be Wood.  (note Wood fails because of the presence of Bowling Green)

I am preparing an alternate definition.   County in MSA, urbanized area has largest urban area share of county population, and urban population > 50% of county population.  That should be a more limited trimming than my list.

[Torie]

The CBSA concept appears to have a lot of potential. It would be nice to have a map of only those CBSA's that take in two or more counties, since single county CBSA's don't matter for our purposes.

[jimrtex]

These changes are based on the following definition:

County is (1) constituent of a metropolitan statistical area; (2) an urbanized area is the most populous urban area in the county; (3) and 50% or more of the county population is in urban areas (alternatively, less than half the county's population is rural.

Thus qualifying counties are either (a) a central county of the MSA (1 and 2 are necessary conditions) and have a mostly urban population; or (b) an outlying county, that had been initially identified as a central county of a metropolitan statistical area, but that had been merged into another CBSA based on commuting, and has a mostly urban population.

Counties of type (b) had either initially been identified by a pseudo core (eg South Lyon-Howell UA) or a weak core (eg Port Huron UA). 

Counties that are excluded by the 50% urban requirement were misidentified as urbanized counties based on the Census Bureau using a single criteria for both Metropolitan and Micropolitan statistical areas (ie 5,000 persons in the county in the largest urbanized area).   5,000 persons is between 10% and 50% of an urban cluster that is a core.  It is less than 10% of an urbanized area that is a core, and thus some counties that are fairly peripheral to the urbanized area, are classified as being "central" to the metropolitan area.  These counties are really bedroom counties, but have some people sleeping on the couch in the living room.

Alabama:
Montgomery (trim Elmore) 46% urban.

Arkansas:
Fort Smith (trim Crawford) 48% urban.

Connecticut:
Torrington (eliminate Litchfield).  Bridgeport UA, Danbury UA, Hartford UA, and Waterbury UA come into Litchfield County, but Torrington UC is the most populous urban area.  In part because of multiple target counties for commuting, Litchfield is not an outlying county of any.

Delaware:
Salisbury, MD (add Sussex)  Salisbury, MD urbanized area is the largest urban area, in a county with a bunch of small urban clusters, such that Sussex County is 59% urban.

Georgia:
Athens (trim Oconee) 49.6% urban.
Dalton (trim Murray)  30% urban.   I had misstated that Dalton was in Chattanooga, TN MSA.

Indiana:
Terre Haute (trim Clay) 39% urban.

Kansas:
St.Joseph, MO (trim Doniphan) 30% urban.  The portion of St. Joseph UA in Doniphan is so small (2368) it does not even qualify as a central county under the Census Bureau definition.

Kentucky:
Clarksville, TN (trim Christian) Hopkinsville UC is largest UA in county.

Louisiana:
Baton Rouge (trim Iberville) 41% urban.

Maine:
Portland (trim York) 43% urban. 
Bangor (eliminate Penobscot) 42% urban.

Maryland:
Balltimore (trim Queen Anne's) 46% urban.
California-Lexington Park (eliminate St.Mary's) 49.6% urban.

Michigan:
Lansing (trim Clinton) 47% urban.

Minnesota:
La Crosse, WI (trim Houston) 43% urban.

Mississippi:
Hattiesburg (trim Lamar) 49.6% urban.

North Carolina:
Asheville (trim Haywood) 45% urban.

Ohio:
Wheeling, WV (trim Belmont) 45% urban.

Oklahoma:
Oklahoma City (trim Logan) 45% urban.
Tulsa (trim Creek)  46% urban.

Pennsylvania:
Bloomsburg (trim Montour) 46% urban.
Gettysburg (eliminate Adams) 46% urban Hanover Urbanized Area qualifies the county as a central county of a metropolitan statistical area, but Hanover is in York County with a long flanking arm down the York Pike into Gettysburg.   York (City) Urbanized Area is the much larger urban area that qualifies York County.  York-Hanover MSA consists of York County, while Gettysburg MSA consists of Adams County (MSA are named based on the largest city, regardless of the urban area that forms the core).

South Dakota:
Sioux City, IA (trim Union) 39% urban.

Tennessee:
Kingsport (trim Hawkins) 42% urban.

Texas:
Beaumont (trim Hardin) 48% urban.

Virginia:
I had to restore 3 independent cities to their original county to maintain the counties as part of the urban county cluster.  I suspect that best solution would be to treat all IC as part of their original counties.

Kingsport-Bristol-Bristol, TN-VA (trim Washington + Bristol) 46% urban.
Washington, DC (trim Fauqier) 43% urban.
Lynchburg (trim Amherst) 36% urban.
Lynchburg IC added to Campbell to maintain its status.
Petersburg IC added to Dinwiddie to maintain its status as part of Richmond cluster.
Hopewell IC added to Prince George to maintain its status as part of Richmond cluster.
Roanoke (trim Botetourt County) 36% urban.

West Virginia:
Huntington (trim Wayne) 35% urban.
Beckley (trim Fayette) 42% urban.

[muon2]

So does this definition put Wood, OH with Toledo? The percentages are 41.97% UA, 28.48% UC, leaving 29.55% rural. You said it would fail before because of Bowling Green, but this new definition appears to simplify things so that one doesn't need that level of detail.

I started looking at some of the OH competition plans, since minimizing county fragments and increasing compactness were both goals. There was a 0.5% population deviation maximum for the districts. Instead of using our concept of microchops which don't count, there was a rule that allowed a chop without penalty that exactly included the part of municipality that crossed the county line. It is possible to view the top scoring plans in terms of apportionment regions, and the 1st and 2nd place plans are shown below. The plan on the left was better for compactness and the plan on the right had fewer fragments seen as more regions. It is interesting that neither plan preserves the metro areas we are identifying.

 

[Torie]

I believe my final Ohio plan did preserve all the urban clusters no? I am a bit confused about what you guys are talking about, about Wood. I get confused a lot on these matters.

[muon2]

I believe my final Ohio plan did preserve all the urban clusters no? I am a bit confused about what you guys are talking about, about Wood. I get confused a lot on these matters.

I think this is the OH plan you refer to.

There are quite a few chops and splits of counties in the clusters that I see. In order to test urban cluster preservation the plan has to be reduced to a set of whole county apportionment regions. County clusters may not span different regions in a state.

Ideally there should be no population shifts between regions while providing districts within 0.5% of the quota. In practice up to one microchop may be used between any two regions to get districts within that limit. If a regular chop is needed, then those two regions are a single larger apportionment region. Chops used within a region should be kept to a minimum.

Maximizing the number of valid apportionment regions is equivalent to minimizing the number of regular chops. That chop count has to be balanced against erosity and the court will expect that for a given set of criteria (ie chop count and erosity) the population range between the most and least populous district will be minimized.

[jimrtex]

So does this definition put Wood, OH with Toledo? The percentages are 41.97% UA, 28.48% UC, leaving 29.55% rural. You said it would fail before because of Bowling Green, but this new definition appears to simplify things so that one doesn't need that level of detail.

I started looking at some of the OH competition plans, since minimizing county fragments and increasing compactness were both goals. There was a 0.5% population deviation maximum for the districts. Instead of using our concept of microchops which don't count, there was a rule that allowed a chop without penalty that exactly included the part of municipality that crossed the county line. It is possible to view the top scoring plans in terms of apportionment regions, and the 1st and 2nd place plans are shown below. The plan on the left was better for compactness and the plan on the right had fewer fragments seen as more regions. It is interesting that neither plan preserves the metro areas we are identifying.

 

With my alternate definition the urban county clusters would be:

Youngstown: Mahoning, Trumbull
Akron: Summit, Portage
Cleveland: Cuyahoga, Lorain, Lake, Medina
Columbus: Franklin, Delaware, Licking, Fairfield
Dayton: Montgomery, Greene, Miami
Cincinnati: Hamilton, Butler, Warren, Clermont
Toledo: Lucas, Wood

Single county clusters:
Lima: Allen
Springfield: Clark
Mansfield: Richland
Weirton-Steubenville WV-OH: Jefferson
Huntington-Ashland, WV-KY-OH: Lawrence

What I was trying to capture with the 25% threshold was where urbanized areas were a significant part of a county's population, and implied additional urban population or urban fringe population (not classified as urban, but much higher density than economically-viable agriculture will support).

The latest definition requires that an urbanized area be the largest urban area in the county.  That is, it would be the urban area that we would choose if we had to select a single  urban area that best characterized the county's settlement pattern (and is quite similar to the procedure used by the Census Bureau when defining the initial set of central counties).

For the most part, the 25% total urbanized area threshold assured we had picked the largest urban area.  Exceptions were Sussex, DE, where Salisbury UA had 21% of the population, along with a bunch of urban clusters, and Litchfield, CT, where several urbanized areas produced a relatively high percentage, but not in any single one, such that Torrington UC was the largest core.

But adding the 50% urban criteria actually demonstrates a concentration of spatially-associated population, rather than the previous implied settlement.

The counties that are trimmed under my latest standard are typically low population (less than 100,000) and where an urbanized area has crossed the boundary, but not had a strong enough presence to produce related population growth.   A county  with less than 50% urban population simply is not a concentrated high density population.  Though it might qualify as a "central county" it functions as an "outlying county".

What I was say with regard to Wood, was that Bowling Green UC with the 24% of the population, was keeping Toledo UA at 42% from reaching a higher share of the population.

The district along Lake Erie in the contest plans could be considered a Bowling Green-Port Huron to Elyria-Lorain district, but using the urban county definition it is a Toledo to Cleveland district.

I didn't really like the Ohio rule for cities crossing county lines.   It was too much a gimmick, and basically said it was OK to split the city, but you could also split the county.   If you wanted to consider splitting cities and townships something to have priority over splitting counties (which is certainly the priority expressed with regard to House districts in the constitution), I would rationalize the political geography.

A city that crossed a county line would be considered to be in the county in which it had the most population (eg Franklin County would be extended outward to encompass all of Columbus, for districting purposes).   The same would be done for municipalities in multiple townships, and a municipality that had absorbed a township in part, would absorb all townships throughout its territory.

[jimrtex]

I believe my final Ohio plan did preserve all the urban clusters no? I am a bit confused about what you guys are talking about, about Wood. I get confused a lot on these matters.

I think this is the OH plan you refer to.

There are quite a few chops and splits of counties in the clusters that I see. In order to test urban cluster preservation the plan has to be reduced to a set of whole county apportionment regions. County clusters may not span different regions in a state.

Ideally there should be no population shifts between regions while providing districts within 0.5% of the quota. In practice up to one microchop may be used between any two regions to get districts within that limit. If a regular chop is needed, then those two regions are a single larger apportionment region. Chops used within a region should be kept to a minimum.

Maximizing the number of valid apportionment regions is equivalent to minimizing the number of regular chops. That chop count has to be balanced against erosity and the court will expect that for a given set of criteria (ie chop count and erosity) the population range between the most and least populous district will be minimized.

I think his Columbus cluster is OK.  The counties added to get to three districts don't have to be together.  The idea is to keep the 3 districts Columbus-centric.

It should pretty easy to get Lucas+Wood into a 1-district region.

Cincinnati+Dayton can probably go into a 4-district region.   4 plus 1, is just as good as 3 plus 2, and arguably better since the one is a non-metro district rather than putting a larger area under the domination of the large cities.

In northeast Ohio, Summit+Portage might have to be used.

[muon2]

I believe my final Ohio plan did preserve all the urban clusters no? I am a bit confused about what you guys are talking about, about Wood. I get confused a lot on these matters.

I think this is the OH plan you refer to.

There are quite a few chops and splits of counties in the clusters that I see. In order to test urban cluster preservation the plan has to be reduced to a set of whole county apportionment regions. County clusters may not span different regions in a state.

Ideally there should be no population shifts between regions while providing districts within 0.5% of the quota. In practice up to one microchop may be used between any two regions to get districts within that limit. If a regular chop is needed, then those two regions are a single larger apportionment region. Chops used within a region should be kept to a minimum.

Maximizing the number of valid apportionment regions is equivalent to minimizing the number of regular chops. That chop count has to be balanced against erosity and the court will expect that for a given set of criteria (ie chop count and erosity) the population range between the most and least populous district will be minimized.

I think his Columbus cluster is OK.  The counties added to get to three districts don't have to be together.  The idea is to keep the 3 districts Columbus-centric.

It should pretty easy to get Lucas+Wood into a 1-district region.

Cincinnati+Dayton can probably go into a 4-district region.   4 plus 1, is just as good as 3 plus 2, and arguably better since the one is a non-metro district rather than putting a larger area under the domination of the large cities.

In northeast Ohio, Summit+Portage might have to be used.

I think we agree on this, let me confirm that. The multi-county clusters in OH and their number of districts is:
Youngstown: Mahoning, Trumbull (0.623)
Akron: Summit, Portage (0.975)
Cleveland: Cuyahoga, Lorain, Lake, Medina (2.751)
Columbus: Franklin, Delaware, Licking, Fairfield (2.289)
Dayton: Montgomery, Greene, Miami (1.108)
Cincinnati: Hamilton, Butler, Warren, Clermont (2.192)
Toledo: Lucas, Wood (0.787)

In general one anticipates that each county cluster would go into a region made up of a number of districts rounded up to the next whole number. The remaining counties would be grouped into single district regions. Clusters that are proximate to one another can be placed into a single larger region. Regions can also be merged to facilitate chops designed to reduce erosity. When a single region includes two adjacent clusters, districts may split the clusters to reduce chops and erosity.

In OH, there are no small counties that can bring the Akron cluster up to the level of a one district quota, and the population can't be made up by microchops alone. Therefore Akron will have to combine with either the Cleveland or Youngstown cluster, or single counties including Stark. One possibility that occurs with a Cleveland merger is that it may may more sense to split Summit and Portage to maintain other district criteria. For example:



The Cleveland and Akron clusters can combine with Geauga and Ashtabula to form a compact region with 3.997 CDs, so no microchops with any other region are necessary. By combining Summit and Medina only a microchop using Oakwood brings it to within quota, this also provides for a much less erose CD 14 which otherwise would have to wrap around the south edge of Cuyahoga to get enough population within this region. The districts are all well within the Cleveland CSA, so the split of Summit from Portage at the district level works for me.

[jimrtex]

I believe my final Ohio plan did preserve all the urban clusters no? I am a bit confused about what you guys are talking about, about Wood. I get confused a lot on these matters.

Wood County is 42% Toledo Urbanized Area, 24% Bowling Green Urban Cluster, and the rest rural or small Urban Clusters.

Under my first definition it qualified because it was part of the Toledo MSA, and more than 25% of the county was in urbanized areas (urbanized areas have a population greater than 50,000, urban clusters have less than 50,000.  Size is the only distinction between urbanized areas and urban clusters.

Muon had questioned where the 25% threshold came from.   Answer: it seemed to be a reasonable number to me.   Typically, if you have a large urban area, it has a much higher share of the population, since at 1000 person per square mile, a small area of a county, say 10% can have a lot of people.   So most counties with part of an urbanized area have most of their population in that urbanized area, or very little.  25% was in sort of a middle area, not including too many counties which really weren't densely populated.  Or in actuality populated densely.  For example, San Berndardino County is not densely populated, but the areas that are populated, are populated densely).  25% also did not exclude many counties where the urbanized area was really characterizing the population distribution.

I had also reasoned that if an urbanized area had 25% of a county's population, that there would be additional population nearby, which while not in the urbanized area, but was closely tied economically to a city where they did everything but sleep and mow the lawn.  They not only worked in the city, but shopped in the city.

But I had examined what would happen if I had increased the threshold to 50% or reduced it to 15%.  Wood County would have been excluded from the Toledo cluster if the threshold had been increased to 50%,

But under my new proposal it would qualify.  The largest urban area in the county is Toledo Urbanized area.  If you were characterizing where the population lives, "Toledo suburbs" is an accurate answer.  If you said "a mix of Toledo suburbs, Bowling Green, and rural", you would also be accurate, possibly more accurate.  But we are only permitting one answer.

Which in this case is "Toledo suburbs and most of the population is urban."

If Ohio were to create metropolitan governments, and did it in a rational fashion, it would likely split Wood County. 

We could do the same with respect to redistricting, but it is unlikely to be done in a way than wouldn't be interpreted as meaning, "so us pols can put Kaptur and Kucinich in the same district after all."

[Torie]

Wood is chopped anyway, so just because its rural portion was in another CD, should not add another chop should it? I thought this urban cluster thing, was to count as chops un-chopped counties which excise a portion of an urban cluster.

[muon2]

Wood is chopped anyway, so just because its rural portion was in another CD, should not add another chop should it? I thought this urban cluster thing, was to count as chops un-chopped counties which excise a portion of an urban cluster.

There's a difference between discouraging unneeded chops into metros and allowing chops of counties that avoid the urban parts. Part of the exercise is to make the process easy to use. Forcing the mapmakers to first group counties before chopping strongly limits gerrymanders, and allowing one chop for each district as in MI can create significant openings for gerrymanders. The trick is to prefer plans that force microchops or less since their small size provides superior resistance to gerrys.

[Torie]

Wood is chopped anyway, so just because its rural portion was in another CD, should not add another chop should it? I thought this urban cluster thing, was to count as chops un-chopped counties which excise a portion of an urban cluster.

There's a difference between discouraging unneeded chops into metros and allowing chops of counties that avoid the urban parts. Part of the exercise is to make the process easy to use. Forcing the mapmakers to first group counties before chopping strongly limits gerrymanders, and allowing one chop for each district as in MI can create significant openings for gerrymanders. The trick is to prefer plans that force microchops or less since their small size provides superior resistance to gerrys.

And therefore ... ?

[muon2]

Wood is chopped anyway, so just because its rural portion was in another CD, should not add another chop should it? I thought this urban cluster thing, was to count as chops un-chopped counties which excise a portion of an urban cluster.

There's a difference between discouraging unneeded chops into metros and allowing chops of counties that avoid the urban parts. Part of the exercise is to make the process easy to use. Forcing the mapmakers to first group counties before chopping strongly limits gerrymanders, and allowing one chop for each district as in MI can create significant openings for gerrymanders. The trick is to prefer plans that force microchops or less since their small size provides superior resistance to gerrys.

And therefore ... ?

the map would not qualify.

You don't identify regions that will preserve the county clusters. Your map is so laser-focused on rectangular shapes to achieve your vision of non-erosity that you use nearly the maximum-minimum number of chops. In principle there should be no need for more than one chop for each district beyond one. Hamilton, Clermont, Warren, Hocking, Fairfield, Franklin, Putnam, Wood, Knox, Stark, Summit, Columbiana, Cuyahoga (2). That's 14 out of a maximum-minimum count of 15. From what I see only Belmont is a microchop. Going to an extreme in minimizing erosity is just as out of balance as the test maps I draw where I preserve counties at all cost. There's utility in such exercises, but only to set limits and balance points.

[Torie]

How does my map not preserve urban clusters again (I mean, I made a deliberate effort to keep them together)? And would you mind posting the map that reduces the chops?  I mean, if it is erosity city, then depending on how we calculate the erosity score (a task still almost totally undone in my opinion), maybe whatever additional chops I have would be more than counterbalanced by the respective erosity scores.

[muon2]

How does my map not preserve urban clusters again (I mean, I made a deliberate effort to keep them together)? And would you mind posting the map that reduces the chops?  I mean, if it is erosity city, then depending on how we calculate the erosity score (a task still almost totally undone in my opinion), maybe whatever additional chops I have would be more than counterbalanced by the respective erosity scores.

I would say you made a deliberate effort to keep the urbanized areas together, and that is not the same as keeping the counties together. I have intentionally avoided mixing specific definitions of erosity into this thread because I think jimrtex has hit on a valuable concept in building a plan. That means understanding this definition of urban clusters and how they should apply in the context of apportionment regions.

In your plan you have two regions, a south region with 1,2,5,6,7 and 10, and a north region with the rest. Even with only two regions, you have split Miami from the region that includes the rest of the Dayton cluster. There are a huge number of possible region groupings using the rules we've started in this thread. My interest is to see if these rules provide reasonable constraints forcing maps towards specific goals.

[jimrtex]

I believe my final Ohio plan did preserve all the urban clusters no? I am a bit confused about what you guys are talking about, about Wood. I get confused a lot on these matters.

I think this is the OH plan you refer to.

There are quite a few chops and splits of counties in the clusters that I see. In order to test urban cluster preservation the plan has to be reduced to a set of whole county apportionment regions. County clusters may not span different regions in a state.

Ideally there should be no population shifts between regions while providing districts within 0.5% of the quota. In practice up to one microchop may be used between any two regions to get districts within that limit. If a regular chop is needed, then those two regions are a single larger apportionment region. Chops used within a region should be kept to a minimum.

Maximizing the number of valid apportionment regions is equivalent to minimizing the number of regular chops. That chop count has to be balanced against erosity and the court will expect that for a given set of criteria (ie chop count and erosity) the population range between the most and least populous district will be minimized.

I think his Columbus cluster is OK.  The counties added to get to three districts don't have to be together.  The idea is to keep the 3 districts Columbus-centric.

It should pretty easy to get Lucas+Wood into a 1-district region.

Cincinnati+Dayton can probably go into a 4-district region.   4 plus 1, is just as good as 3 plus 2, and arguably better since the one is a non-metro district rather than putting a larger area under the domination of the large cities.

In northeast Ohio, Summit+Portage might have to be used.

I think we agree on this, let me confirm that. The multi-county clusters in OH and their number of districts is:
Youngstown: Mahoning, Trumbull (0.623)
Akron: Summit, Portage (0.975)
Cleveland: Cuyahoga, Lorain, Lake, Medina (2.751)
Columbus: Franklin, Delaware, Licking, Fairfield (2.289)
Dayton: Montgomery, Greene, Miami (1.108)
Cincinnati: Hamilton, Butler, Warren, Clermont (2.192)
Toledo: Lucas, Wood (0.787)

In general one anticipates that each county cluster would go into a region made up of a number of districts rounded up to the next whole number. The remaining counties would be grouped into single district regions. Clusters that are proximate to one another can be placed into a single larger region. Regions can also be merged to facilitate chops designed to reduce erosity. When a single region includes two adjacent clusters, districts may split the clusters to reduce chops and erosity.

In OH, there are no small counties that can bring the Akron cluster up to the level of a one district quota, and the population can't be made up by microchops alone. Therefore Akron will have to combine with either the Cleveland or Youngstown cluster, or single counties including Stark. One possibility that occurs with a Cleveland merger is that it may may more sense to split Summit and Portage to maintain other district criteria. For example:



The Cleveland and Akron clusters can combine with Geauga and Ashtabula to form a compact region with 3.997 CDs, so no microchops with any other region are necessary. By combining Summit and Medina only a microchop using Oakwood brings it to within quota, this also provides for a much less erose CD 14 which otherwise would have to wrap around the south edge of Cuyahoga to get enough population within this region. The districts are all well within the Cleveland CSA, so the split of Summit from Portage at the district level works for me.

"Anticipates" might be too strong of a word, since it may cause a map drawer to miss the opportunity, for example, to place the Dayton and Cincinatti clusters into a single region, that only has to encompass 500,000 persons outside the cluster, rather than 1.2 million persons outside the two areas combined.  Rounding up does set some sort of outer limit, but could produce fewer apportion regions than competing plans.

Akron is within 5%.  So I would go ahead and add Geauga and Ashtabula to bring Cleveland up to 3.022.  You have more regions, and the correction is quite localized, since the excess in Cuyahoga complements the deficit in  Moving 15,000 persons from Medina or Geauga is not grossly disrespecting counties given the density of population.

Note that under my rules, it is also possible to create an apportionment region entirely within a cluster.  This might work for Montgomery+Greene, and then Miami would be place in another region.   Since the region will eventually have to be split, it is OK to split it now, if we can at this stage.

[muon2]

As I understand the concept of the urban clusters applied to OH, one could start with a regional plan like this one. It's certainly not the only one, but it's the one I used to produce the NE OH picture I posted earlier.



Each of the seven clusters identified by jimrtex is embedded in a single region. The deviations are small enough that only microchops are needed to balance population between regions. Akron is merged with the Cleveland cluster and the Dayton and Cinci clusters are together. If one doesn't like the shape of the Youngstown region it can be combined with the Canton region using a chop in Stark to improve the shape. That's the type of tradeoff that should be permitted, one less region for less erosity.