Neutral redistricting criteria

Neutral criteria typically divide into two categories. One set of criteria are based solely on geography and demographic data. The other set depends on political data.

Population Equality

The most important piece of demographic data is the population. The goal is to have districts with nearly equal populations. For a state with k districts and a total population P, the quota for each district is P/k.

Ideally each district should have a population as close as possible to the total population. In order to achieve other geographic goals, it may be necessary to have small variations from the quota. One measure is the range, which is the difference between the largest and smallest district expressed as a percentage of the quota. State and federal laws limit the size of the range, and it can vary for different types of districts, for example state legislative districts may permit a larger range than congressional districts.

Another measure is the maximum deviation. This is the maximum absolute percentage difference permitted for a district from the quota. This is generally set by state or federal law, and may be set at half the maximum permitted range if range is the appropriate legal standard.