Gerrymandering - Voting Systems

Voting Systems

Gerrymandering is used most often in favor of ruling incumbents or a specific political party—the one drawing the map. Societies whose legislatures use a single-winner voting system are the most likely to have political parties that gerrymander for advantage. Most notably, gerrymandering is particularly effective in non-proportional systems that tend towards fewer parties, such as first past the post.

Most democracies have partly proportional electoral systems, where several political parties are proportionally represented in the national parliaments, in proportion to the total numbers of votes of the parties in the regional or national elections. In these more or less proportional representation systems, gerrymandering has little or less significance.

Some countries, such as Australia, Canada, and the UK, authorize non-partisan organizations to set constituency boundaries in an attempt to prevent gerrymandering. Gerrymandering is most common in countries where elected politicians are responsible for defining constituency boundaries. They have obvious self-interest in determining boundaries to their and their party's interest.