Proportional representation: Difference between revisions
clarifying grammar
Dr. Edmonds (talk | contribs) No edit summary |
Dr. Edmonds (talk | contribs) (clarifying grammar) |
||
Line 1:
{{Wikipedia}}
'''Proportional Representation''' ('''PR''') is a measure of the outcome of an election where there are multiple parties and multiple
In practice,
== Measures ==
There are several metrics which are used to define Proportional Representation explicitly. A well-accepted form is the [[W:Gallagher index|Gallagher index]], which measures the difference between the percentage of votes each party gets and the percentage of seats each party gets in the resulting legislature, and
[[W:Michael Gallagher (academic)|Michael Gallagher]], who created the index, referred to it as a "least squares index", inspired by the residual sum of squares used in the method of least squares. The index is therefore commonly abbreviated as "LSq" even though the measured allocation is not necessarily a least squares fit. The Gallagher index is computed by taking the [[W:Square root|square root]] of half the [[W:Summation|sum]] of the squares of the difference between percent of votes (<math>V_i</math>) and percent of seats (<math>S_i</math>) for each of the political parties (<math>i=1,\ldots,n</math>).
Line 119:
In addition, maximizing the natural log favors small parties a little too much to pass proportional criteria and when a voter’s satisfaction is zero is just the most extreme example of that. The partial sums of the harmonic series equation does however pass the proportional criteria that a maximization of the natural log can’t. I personally think that the partial sums of the harmonic series are better for determining the winners of an election, but the natural log of summed utilities is a better tool for measuring proportionality in computer simulations even if those simulations are skewed to representing small parties too much (which may or may not be a bad thing).
== See Also ==
* [[Vote splitting]]
* [[Proportionate Representation]]
* [[Ideal Representation]]
== Further reading ==
| |||