Allocated Score
Allocated Score is a sequential Multi-Winner Cardinal voting system built on Score voting ballots. Its public branding is Score Then Allocated Rounds or Proportional STAR. This branding is intended to align with single winner STAR voting.
Allocation is the default method of removing voters in a sequential Multi-Member System. Each winner is selected as the Utilitarian winner (ie highest sum of score). After each selection, the Hare quota of ballots which scored that candidate the highest is allocated to this candidate and as such removed from subsequent rounds.
Procedure
Each voter score all candidates on a [0,5] scale
- Select the candidate with the highest sum of score as this rounds winner
- Set the ballot weight to zero for the Quota of voters ballots which gave the highest scores to that winner
- If several voters have given the winner the same score at the threshold of the Quota then Fractional Surplus Handling is applied to those voters
- Repeat this process until all the seats are filled.
Fractional Surplus Handling to break ties: when calculating which ballots belong to a candidate's quota so they should be allocated to them, if for a particular score, including voters that gave that candidate that score in the quota would make the quota to large and excluding it would make it to small, then exhaust a portion of those vote's ballot weights such that the total weight of the exhausted ballots still equals the hare quota. The reason why Fractional Surplus Handling is preferred is that it preserves the Independence of irrelevant alternatives and Monotonicity criteria.
Variants
Quota
A common variant is to use Droop quotas instead of Hare quotas to mitigate Free riding.
Sequential Monroe
Sequential Monroe can be thought of as a variant of Allocated Score with a change to the selection method.