3D swingometer
From Wikipedia, the free encyclopedia
The 3D swingometer is a graphic device used to illustrate the shift in election results from the previous election in a three-party system. It is similar to the '2D' swingometer used in two-party system elections, but uses the extra dimension to allow swings to occur between three parties.
The sum of all the swings between parties must equal zero. In a three party system, the most complicated swings will involve a major swing either to or from one political party, with this swing being made up of two components from each of the other two parties. For instance there may be a 3% swing towards the Red party, consisting of a 2% swing from the Blue party and a 1% swing from the Yellow party. Alternatively, there may be a 5% swing from the Blue party, of which 3% is towards the Yellow party and 2% towards the Red party.
It is possible to split the swing space up into different regions indicating what the result would be if the swing indicated occurred linearly across the electorate. This gives rise to four regions: one each indicating overall control for each party, and a fourth region indicating no overall control.
Where there are swings directly from one party to a second party with the third party's vote remaining unchanged, the 3D swingometer clearly indicates that the third party also benefits slightly from the reduction in vote of the first party.
The three dimensions consist of the two used to create the swing space and the third for the pendulum to swing in.
