What is Polsby Popper?

Polsby Popper score is a measurement calculated by taking the ratio of the area of a district to a circle whose circumference matches the perimeter of the district. The score of this calculation measures from 0 to 1. The higher the score is, the more compact the shape is. Here are a few shapes that have a Polsby Poppy Score, which is essentially a calculation of their overall compactness. 

For a Circle,  using the universal formula: PoPo(s) = 4πAP2 produced a Polsby Popper score of exactly 1, which indicates optimal compactness. Conversely, a right-angle triangle produced a Polsby Popper score of about .4, showing a decrease in the level of compactness. The most common shape found in the gerrymandering of political districts is squares. Analyzing its Polsby Popper score of 0.7854, not only indicates that it is more compact than the right angle triangle, but it brings emphasis to the universal compactness score for the square. 

In the United States, there are 435 congressional districts and the average compactness score is .271 while the standard deviation is .117. These numbers indicate the congressional district are not determined from geographical whereabouts with the goal of compactness is mind. But, the drawing of congressional states can be influenced by gerrymandering and bureaucratic issues.

## # A tibble: 1 × 1
##   `sd(PolsbyPopper)`
##                <dbl>
## 1              0.117
## # A tibble: 1 × 1
##   `mean(PolsbyPopper)`
##                  <dbl>
## 1                0.271

Comparing District to other Shapes(Right Triangle)

When analyzing compactness scores of congressional districts,  we can use basic polygons to offer an ide a of compactness and its nature. For instance, the right triangle is a shape that can be seen or used in everyday life. Right triangles can be seen in tables, books, buildings, and even in geographical boundaries. The compactness score of a right triangle is .4, making it almost equidistant between optimal compactness(1) and inadequate compactness(0).

There are two districts that are in close proximity of this compactness score. The first district is Kansas’ 4th congressional district, which has the Polsby Popper Score of .404. The second district that has a compactness score very close to a right triangle is Pennsylvania’s 11th congressional district, which has a Polsby Popper score of .397. Although these states are both similar in compactness scores of a right triangle, their shapes are not similar to the right triangle and are unalike each other.

Kansas’ 4th District: .404

Pennsylvania District 11: .397

Comparing Congressional Districts with Similar Compactness scores, Geographical Differences (Hawaii 2 vs Louisiana 2)

The following maps represent both Hawaii’s and Louisiana’s second district, whom both have almost identical compactness scores. Louisiana’s second district has a Polsby Popper score of .0623, which is very similar to Hawaii’s second district’s score of, .0623. Although the compactness cores of the two districts shows a high association between them, the zoomed in maps of the two districts show great geographic differences. When discussing the distinct geographical features that states like Hawaii and Louisiana, one may think the compactness scores of these states’ districts are heavily influenced. 

Hawaii is a very unique state when discussing its geographical features, it has mountains, volcanoes, valleys, and it is made up of islands. In comparison to the island hovering in the middle of the Pacific ocean, Louisiana has bodies of water that run through the state.  Amongst these bodies of water are the Mississippi River , the Red River, and the Gulf of Mexico . Another geographic feature that it is mainly flatland, and much of the state is below sea level.

Louisiana District 2

Hawaii District 2

Politics: Major cause of Gerrymandering and Influencing Compactness Scores

Maryland’s District 3

Before being acknowledged as one of the most gerrymandered district in the United States, Maryland’s 3rd district was fairly compact prior to its redrawing in 2011. As a result of redistricting, the Polsby Popper score of this district is now at .037, the second lowest in the United States. The primary motive of this district’s redrawing was to cater to the Democratic party. Democrats have benefited from this redrawing by shifting wealthier democratic voters from other areas to this district, which can later become sponsors for their candidacy. 

Another reason why the 3rd district in Maryland is shaped like a “Pterodactyl” (Washington Post) is to maximize the representation of minority communities. The redrawing of this district allowed minority dominate counties like Baltimore. The primary benefitor of the redistricting and gerrymander, Gov. John Sarbanes, believes that the shape of the district is just a feature, not a bug(Washington Post). He recognizes that his position is guaranteed because of the gerrymandering and catering towards democratic candidates. Yet, he claims he does not take his position for granted and he still prioritizes the needs of the voters. 

Texas’ 33rd District

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## → Please use `set_pop_tol()` to update your <redist_map> or create a new
##   <redist_map> with the correct number of districts.

The 33rd congressional district of Texas was created as a result of the United States census in 2010. Until 2021, four million new residents had been gained; of that 95% were people of color and half were Hispanic (Texas Tribune). These four million residents added to the population allowed for two additional U.S House seats in the 2012 House elections. The controversy regarding Texas’ 33rd district is the alleged attempt to dilute the Latino population, ultimately weakening Latino voting strength and diminishing their ability to have a broader influence (Texas Tribune).

In 2013, the three largest ethnic groups in congressional district 33 were: White (Hispanic), “Other” (Hispanic) and White (Non-Hispanic) with a 44.4%, 19.1% and 15.7% share of the district’s population respectively. Eight years later, the demographics and figures have since changed, as now the three largest ethnic groups include the unchanged yet decreased White (Hspanic) and “Other” (Hispanic) and the graduation of Black or African-American (Non-Hispanic). The population of White (Hispanic) has since decreased to 35.4%, the Other (Hispanic) population has also decreased to 20.8% and the Black/ African American has remained the same from 2013 at 15.7% of the population but increased as one of the major ethnic groups in the district.

The redistricting of the 33rd congressional district of Texas has created a miniscule compactness score of .058. As a result of the 33rd district being tightly packed in an attempt to gather and then dilute the voting strength of the Latino population, the Polsby Popper score reflects this with a score extremely close to zero. Which is the second lowest score in the whole of the United States of America.

Texas’ 35th District

Like Texas’ 33rd congressional district, its 35th was created as a result of the United States census in 2010. Although there is no controversy regarding the redistricting of district 35, it cannot go without being said that there has been a shift in ethnic majorities in the region. 

In 2013, White (Hispanics) held 43.8% of the population in the region with 313,000 residents, while the White (Hispanics) retained 24.9% of the population having 178,000 residents and the “Other” (Hispanic) population included 118,000 residents. “In 2021, there were 1.34 times more White (Hispanic) residents (284k people) in Congressional District 35, TX than any other race or ethnicity. There were 212k White (Non-Hispanic) and 98.9k Other (Hispanic) residents, the second and third most common ethnic groups” (DataUSA). Similarly to the 33rd district, the result of attempting to confine the Hispanic population into one district, to produce an influenced result in U.S. House elections have resulted in an extremely low Polsby Popper score of 0.59 a great level of compactness in the region. Which is the third lowest score in the entirety of the United States of America.

Louisiana’s 2nd District

Louisiana’s 2nd congressional district is among one of the oldest congressional districts in the United States of America. Established in 1823 as a part of the 18th United States Congress, it has grown from containing nearly all of New Orleans to stretching west in Baton Rouge as well as all of the city of New Orleans.

The most up-to-date diversity and population of the 2nd congressional district is majority Black or African-American accounting for approximately 60.3% of the population. According to the American Community Survey, “In 2021, there were 2.23 times more Black or African American (Non-Hispanic) residents (472k people) in Congressional District 2, LA than any other race or ethnicity” (DataUSA). The preceding largest ethnic groups include White (Non-Hispanic) and Other (Hispanic), recording a 27% and 2.59% share of the population. However, compared to the statistics in 2013 there shows a change in the diversity of the population. Reflecting a slight decrease in the Black/ African American and White (Non-Hispanic) population and a shift in the White (Hispanic) population, from contributing to 3.12% of the population to 2.56% of the population.

Since 1984, the district has been drawn as a black-majority district and has now gained the controversy of whether the Louisiana congressional map should now include two majority-Black congressional districts. Per the case Robinson v. Ardoin, “Louisiana’s Black population exceeds 30%, which the court said merits a second Black district out of six total” (LA Illuminator). The NAACP Legal Defense Attorney Jared Evans plans to proceed with a lower court hearing February 4th, 2024 to have new maps drawn.

Histogram: Mean Compactness for All States

When finding what Polsby Popper scores are the least and most common between all district’s across the 44 states measured, a histogram can be used to find which ranges of scores are the most probable. The following histogram analyzes the Polsby Popper score of the districts within a state. The Histogram has a unimodal and fairly symmetric shape, which indicates that there is a range of score that is most common between districts. The most common range of scores is .15 to .3 and it is further highlighted by a peak at the Polsby Popper score of .22.

## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

The histogram shown above represents all of the mean Polsby Popper score each state’s districts have. The colors are need to help differentiate each state’s Polsby Popper score.

Summary Statistics for Polsby Popper

## # A tibble: 1 × 1
##   `sd(PolsbyPopper)`
##                <dbl>
## 1              0.117
## # A tibble: 1 × 0
## # A tibble: 1 × 1
##   `IQR(PolsbyPopper)`
##                 <dbl>
## 1               0.159

References:

“Congressional District 2, La.” Data USA, Data USA, datausa.io/profile/geo/congressional-district-2-la#languages.

“Congressional District 33, TX.” Data USA, Data USA, datausa.io/profile/geo/congressional-district-33-tx#demographics.

“Congressional District 35, TX.” Data USA, Data USA, datausa.io/profile/geo/congressional-district-35-tx#demographics.

Guo, Jeff. “Welcome to America’s Most Gerrymandered District.” The New Republic, 8 Nov. 2012, newrepublic.com/article/109938/marylands-3rd-district-americas-most-gerrymandered-congressional-district.

Muller, Wesley. “Supreme Court Ruling in Louisiana Redistricting Case Creates Uncertainty.” Louisiana Illuminator, Louisiana Illuminator, 21 Oct. 2023, lailluminator.com/2023/10/21/louisiana-redistricting/.

United States Census Bureau. Congressional Districts (113th Congress) https://www2.census.gov/geo/maps/cong_dist/cd113/cd_based/ST15/CD113_HI02.pdf.

United States Census Bureau. Congressional Districts (113th Congress) https://www2.census.gov/geo/maps/cong_dist/cd113/cd_based/ST22/CD113_LA02.pdf.

Ura, Alexa. “First Lawsuit Filed Challenging New Texas Political Maps as Intentionally Discriminatory.” The Texas Tribune, The Texas Tribune, 18 Oct. 2021, www.texastribune.org/2021/10/18/texas-redistricting-lawsuit/.

Zalesk, Andrew. A Tour of What May Be the Nation’s Most Bizarrely Gerrymandered ..., Washington Post, 11 Feb. 2019, www.washingtonpost.com/lifestyle/magazine/a-tour-of-what-may-be-one-of-the-nations-most-bizarrely-gerrymandered-districts/2019/02/08/6351ef22-232b-11e9-ad53-824486280311_story.html.