Open List/Delegated (OL/D) voting

From electowiki

Open List/Delegated voting (OL/D voting, pronounced "old voting") is a proportional voting method for electing legislators to a multi-seat body. It assumes the voters have been divided up into one equal-population locality (aka riding, district, or constituency) per seat being elected and that each candidate has publicly declared their preference order for the other candidates ("if I don't win, then I want the votes I hold to go to her, then him, then him, etc.").

Voters make two different choices in each race:

  1. Choose a candidate.
    • The ballot lists the candidates running locally, with their parties and their first three transfer preferences (explained below).
    • Voters may write in candidates from further away.
  2. Choose a transfer method for when your first choice is no longer in the running. There are 2 basic options, and voters can also choose to go half and half:
    • Trust your party’s voters (that is, the voters of your chosen candidate’s party.)
    • If your first choice is no longer in the running, your vote is transferred to the remaining candidates from your chosen party, in proportion to the number of direct votes they got.
    • If every voter chose this option, this would be like an “open list” voting method; that is, seats would be divided proportionally by party, and go to the highest vote-getters within the party.
    • This is the default if you vote for a local, non-independent candidate.
    • If you choose this option, your vote will never be transferred out of the party. Since independent candidates are considered to each be in a party by themselves, voters for those candidates should only choose this option if they do not want their vote to be transferred.
    • Trust your candidate (that is, the pre-declared preferences of your chosen candidate.)
    • Each candidate must publicly pre-declare ordered preferences between the other candidates. If the candidate is no longer in the running, these votes will go to the highest remaining candidate on their pre-declared preference list.
    • This is the default if you vote for a non-local and/or independent candidate.

The basic vote-counting process has 5 steps (based on Single Transferrable Voting):

  1. Tally votes
    • Each ballot counts as 1 point for the chosen candidate.
    • A ballot that supports more than one candidate is still counted as 1 point split equally among the choices. Each of these point fractions will be transferred separately. When one of the fractions is “exhausted”, that amount is transferred to any non-exhausted fractions, split equally.
  2. Eliminate any candidates who got less than a minimum threshold of 25% of the votes of an average locality, unless they are one of the top two candidates in their locality. Transfer those votes.
    • This helps discourage voters from splintering into small single-issue parties. If a party can’t reach 25% in even one locality, it won’t get seats. But those votes will still be transferred, so those voters can still be represented by a relatively sympathetic candidate from a slightly larger party.
  3. Find winners and transfer leftovers
    • If V is the total number of valid (non-exhausted) votes, and S is the number of seats, then a “quota” is defined as Q=V/(S+1). This ensures that each full “quota” of voters will get a seat, with less than one “quota” of vote left unrepresented even though they still have a valid preference.
    • Any candidate with a full quota of votes at any time is elected. If their winning vote total is W>Q, then the leftover fraction (W-Q)/W of all of their votes is transferred.
  4. Eliminate candidate with lowest total and transfer votes
    • See above for the transfer methods a voter can choose.
  5. If there are still seats to fill, repeat from step 3.

Once all seats are filled, each party with at least one seat assigns multi-locality a territory to each of their winning candidate, so that each locality is in the territory of one representative per party.

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