Measuring Fairness

We need an objective, measurable scoring system.

Redistricting is a complex issue combining people, geography, political affiliations, history, and more, making a simple definition of “fairness” difficult. But without clear standards, the Supreme Court has been reluctant to address partisan gerrymandering. That’s why we believe that fair standards must apply a nuanced set of criteria in a way that can be verified through objective tests.

We are actively researching this issue, as new standards are being developed and tested in courts across the country. Our goal is to see what emerges from that process, and use what we learn to enact clear standards for both Congressional and legislative districts before the 2021 redistricting process.

While we need a constitutional amendment to change the way Pennsylvania’s legislative districts are drawn, we don’t need one to change the product (how fair the maps are). This could be addressed by legislation enacted in one legislative session.

Potential criteria

We are currently researching and evaluating several criteria and tests to see how they might work here in Pennsylvania. Those include:

1. Population equality

Key question: Does each district have the same number of people in it?
Equal population across districts means that each person’s vote carries the same power in electing a lawmaker.

Scoring criteria: The maximum population deviation from the ideal.
This is calculated by measuring how much each district’s population varies from the number of people each district should have in it, based on the most recent census figures. The greater the variation, the lower the map scores.

2. Geographic compactness

Key question: Is the shape of each district as regular and simple as possible?
Non-compact districts are not only “unsightly,” they are also difficult to govern because citizens, candidates, and legislators must meet and communicate over unwieldy distances.

Scoring criteria: Total travel time required for all members of each district to travel to a single location.
Using travel time instead of “distance as a crow flies” helps preserve communities like “The Main Line,” built around rail or road infrastructure, and promotes the use of natural borders like major rivers and mountain ranges to separate one district from another. The higher the total travel time, the lower the map scores.

3. Community integrity

Key question: Are counties, cities, and towns kept in a single district, whenever possible?
Breaking defined communities into pieces means they have to coordinate with more legislators—and legislators have more townships competing for their attention. The Pennsylvania Constitution already requires that such splits be avoided, but current practice often ignores this.

Possible scoring criteria: Number of times that a county, city, or township is divided.
The more often this happens, the lower a map scores.

4. Partisan fairness

Key question: Do districts fairly represent voters from all political parties?
When a single political party controls the redistricting process, it may use its influence to “crack” its opponents’ strongholds into pieces small enough so that they cannot win any seats. Conversely, when its opponents are too strong to be “cracked,” it may “pack” them into as few districts as possible.

Possible scoring criteria: Rank all the districts on the map according to their support for each party. Identify the median district, and compare it to statewide numbers from voter registration data or recent major election results.
The goal here is to gauge how closely each party’s support in the median district aligns with its support statewide. For example, let’s say the median district had 40 percent of voters registered to Party A, and 45 percent to Party B. The test would compare these numbers to both parties’ statewide voter registration numbers. If, across the state, 50 percent of voters are registered to Party A, and only 35 percent are registered to Party B, then that shows partisan bias, and the map would receive a lower score.

5. Minimal efficiency gap

Key question: Are the number of “wasted votes” proportional to the number of votes cast for each party?
This standard was introduced and explained by Nicholas Stephanopoulos and Eric McGhee. They define “wasted votes” as “ballots that don’t contribute to victory for candidates,” and say they come in two forms: “lost votes cast for candidates who are defeated, and surplus votes cast for winning candidates but in excess of what they needed to prevail. When a party gerrymanders a state, it tries to maximize the wasted votes for the opposing party while minimizing its own, thus producing a large efficiency gap. In a state with perfect partisan symmetry, both parties would have the same number of wasted votes.”

Possible scoring criteria: What is the difference between the parties’ respective wasted votes in an election, divided by the total number of votes cast?
The higher the efficiency gap, the lower the map scores.

6. Other standards

Researchers are also considering other questions, such as:

As new standards emerge, we’ll consider their value here in Pennsylvania.