Scale invariance: Difference between revisions

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{{Definition|Multiplying every ballot's score of every candidate by a constant <math>\alpha>0</math> should not change the outcome.}}
{{Definition|Multiplying every ballot's score of every candidate by a constant <math>\alpha>0</math> should not change the outcome.}}


The ordinal method criterion is:
The ordinal method criterion is also called the [[homogeneity criterion]]. It is:


{{Definition|For every way of ranking the candidates, multiplying the number of voters who express this preference by a constant <math>\alpha>0</math> should not change the outcome.}}
{{Definition|For every way of ranking the candidates, multiplying the number of voters who express this preference by a constant <math>\alpha>0</math> should not change the outcome.}}

Revision as of 09:11, 6 May 2020

Scale invariance can refer to one of two criteria: a cardinal voting method criterion and an ordinal one.

The cardinal method criterion is:

Multiplying every ballot's score of every candidate by a constant should not change the outcome.

The ordinal method criterion is also called the homogeneity criterion. It is:

For every way of ranking the candidates, multiplying the number of voters who express this preference by a constant should not change the outcome.

Both criteria represent a desideratum that the method should not rely on absolute numbers when selecting a winner, just on the candidates' or factions' relative support.

This page is a stub - please add to it.

References