Surplus Handling: Difference between revisions

In a sequential [[Multi-Member System]] which useuses a [[Quota]] Method to ensure the [[Proportional_representation#Hare_Quota_Criterion |Hare Quota Criterion]] is satisfied, there is an ambiguity about which voters should be in the quota when there are more than needed. This amount is refereedreferred to as a surplus and the various methods to deal with this situation isare referred to as '''surplus handling'''.

In allocation -based systems, the surplus can be transferred to other candidates with some form of '''surplus allocation'''. The number of surplus votes is known;, but none of the various allocation methods is universally preferred. Alternatives exist for deciding which votes to transfer, how to weight the transfers, who receives the votes and the order in which surpluses from two or more winners are transferred.

Reallocation ballots are drawn at random from all of the candidate's votes. This method is more likely than Hare to be representative, and less likely to suffer from exhausted ballots. The starting point for counting is arbitrary. Under a recount, the same sample and starting point is used in the recount (i.e., the recount must only be to check for mistakes in the original count, and not a second selection of votes).

{{quote|While we believe that the Wright System as advocated by Mr. Anthony van der Craats system is sound and has some technical advantages over the PRSA 1977 rules, nevertheless for the sort of elections that we (the PRSA) conduct, these advantages do not outweigh the considerable difficulties in terms of changing our (The PRSA) rules and associated software and explaining these changes to our clients. Nevertheless, if new software is written that can be used to test the Wright system on our election counts, software that will read a comma -separated value file (or OpenSTV blt files), then we are prepared to consider further testing of the Wright system.{{citation needed|date=December 2016}}}}

In [[Cardinal voting systems]] the problem of surplus handing is simplified because the vote aggregation is arithmetic. This means that the surplus voters do not need to be allocated to other candidates. Instead, they can have their ballot weight reduced proportionally to the surplus and the tabulation process can continue unaffected. This method is better than allocation because it is completely deterministic and unbiased. This down-weighting of ballots can be applied to all ballots or to a subset depending on the desired effects and the tabulation system.