Addie Jacobsen — a senior mathematics major at UW Tacoma — presented her math capstone project entitled “Who’s Gerry? Chasing the Math and the ‘Mander on the topic of gerrymandering” on election day, Nov. 6. Jacobsen discussed the history of gerrymandering — the redrawing of congressional districts to try to increase the chances of winning in an election wand how mathematical criteria have been used in an attempt to solve it.
Jacobsen said that her interest was originally drawn to the topic of gerrymandering through a math seminar class that covered how mathematicians attempt to find criteria to solve the problem of gerrymandering.
“I said, ‘That’s really cool; I want to do that,’” Jacobsen said. “I had in my mind that I wanted to do some sort applied math, but I didn’t want to do … pure computer science or physics. That’s why I chose gerrymandering.”
The word gerrymandering first appeared in 1812 and was coined after Elbridge Gerry, the governor of Massachusetts, who had just approved a new redistricting plan that heavily favored a specific political party. The new congressional boundary resembled a salamander and the practice was given the name gerrymander.
As part of the history of gerrymandering, Jacobsen discussed several court cases and papers that have questioned the legality of gerrymandering and tried to come up with mathematical metrics to solve it. The first case that reached the Supreme Court was Baker v. Carr in 1962. Brought to the Tennessee District Court on behalf of a claim that stated the state’s congressional boundaries hadn’t been changed in over 50 years, the case resulted in the ruling that the “redistricting cases were justifiable.”
In 1964, the Reynolds v. Sims case’s ruling called for a new standard for congressional districts in which all districts needed to have a roughly equal population. Davis v. Bandemer in 1984 ruled that there was not sufficient evidence to prove discrimination in any of the districts. As a result, gerrymandering remained a problem.
Wanting to find a solution, two political scientists — Daniel Posby and Robert Popper — created a new metric to measure gerrymandering in their 1991 paper entitled “The Third Criterion: A Procedural Safeguard to Partisan Gerrymandering.” This third criterion — also known as the polsby-popper test — is a measure of the compactness of a shape.
“This metric is telling how much each district looks like a circle,” Jacobsen said. “You can compare it to any other shape. Regardless of what polsby-popper measure we use, is it a good indication of gerrymandering? The answer is no … compactness in general [isn’t] a good criteria (sic) for gerrymandering. It’s been found that we can respect the strict criteria of compactness and still gerrymander.”
In 2004, the Supreme Court ruled on the criterion of compactness. The case — Vieth v. Jubelirer — claimed that Republican congressional representatives were intentionally drawing district boundaries in favor of their party. The court was split in the ruling, but it eventually resulted in a decision to not intervene because of the lack of remedy to the gerrymandering issue.
Jacobsen then discussed another criterion, the efficiency gap. Stemming from the criterion of partisan symmetry, the efficiency gap is voters being grouped into electoral districts in a way that increases wasted votes of one political party and decreases wasted votes of another party.
“Wasted votes are anything over 50 percent for the winning party or any votes for the losing party,” Jacobsen said. “Taking those and subtracting them from each other and dividing it by the total voting turnout is where we get wasted votes. The higher the efficiency gap, the more efficient one party is over the other. And when the efficiency is way too high, it seems suspicious … It sends us a red flag. This party is way too efficient to be [winning]. There has to be a little competition.”
This year, the Supreme Court ruled on the efficiency gap in Gill v.Whitford. The Supreme Court ruled against the plaintiffs that claimed they had a case of gerrymandering against their party. Jacobsen believes that all these cases boil down to an understanding and acceptance of the math used in the different criteria.
Jacobsen concluded that while gerrymandering is still a problem and no criteria have been able to solve it, she hopes that her project will be understood by more than just math majors and create a better appreciation for math.
“We still haven’t found the metrics that measure [gerrymandering] yet,” Jacobsen said. “[But] there still is hope … thus the chase is not over.”