[EM] Open Lists and Closed Lists
Adam Tarr
atarr at purdue.edu
Mon Jul 28 20:04:03 PDT 2003
David,
I read your example as an excellent argument for proportional approval
voting (PAV). Voters can vote across party lines without fear of
supporting a candidate they don't like, and of course it's as easy to vote
in as open list or even multi-winner plurality.
-Adam
>Recently their have been a number of posts regarding the merits of open
>versus closed lists for list PR. I dislike closed lists and feel that
>voters not parties should decide which individuals on a list are elected.
>However the fact that in an open list system a vote counts both for an
>individual and a party list can produce results unintended by the voters.
>Take the following example:
>
>3 parties ( A, B and C) are contesting a 5 seat district. Each party puts
>up a full slate of 5 candidates. Each voter has 3 votes. 100,000 electors
>vote, each voter casts 3 votes.
>
>31% of the voters support party A ( 31,000 voters)
>
>29% of the voters support party B (29,000 voters)
>
>40% of the voters support party C (40,000 voters)
>
>One of the candidates of party B ( B1 ) is a well respected local
>politician who is liked by many of party A's supporters. Another of party
>B's candidates ( B2 ) is very antagonistic to party A.
>
>20% of party A's supporters (6200) vote for candidate B1 and two of their
>own party's candidates.
>
>B1 is also extremely popular with party B supporters and receives one vote
>from almost all of party B's supporters.
>
>Votes received by the candidates of party A and party B are as follows:
>
>A1 26800 B1 34000
>A2 21000 B2 18000
>A3 16000 B3 16200
>A4 12000 B4 15000
>A5 11000 B5 10000
>
>Total votes received by each party are as follows: party A 86800, party
>B 93200,
>party C 120000.
>
>The D'Hondt highest average formula is used to allocate the seats:
>
>Party A 1 seat, party B 2 seats, party C 2 seats. Seats are allocated
>to the candidates on each list who receive the greatest number of votes.
>
>Party B elects candidates B1 and B2.
>
>What would have happened if the 6200 party A supporters hadn't decided to
>vote for B1 and had voted for 3 candidates on their own party's list?
>
>The votes for each party would have been as follows: party A 93000, party
>B 87000, party C 120000. Party A would have obtained 2 seats, party B 1
>seat and party C 2 seats.
>
>The votes for party B candidates would have been as follows:
>
>B1 27800
>B2 18000
>B3 16200
>B4 15000
>B5 10000
>
>Candidate B1 the candidate who obtained the extra 6200 from party A and
>who party A supporters voted for is still elected. B2 who they don't like
>is now defeated.
>
>By voting for a candidate they liked on another list party A's supporters
>have given that list enough extra votes to elect an additional member B2 (
>who they don't like ) and reduced the number of seats obtained by their
>own party from 2 to 1.
>
>Because a vote counts for both a candidate and a party voting for
>candidates on different lists can result in situations like the above
>unintended by the voters and objectionable to them.
>
>The example given above was based on a situation that occurred in the
>French Fourth Republic in which Communist voters cross voting for
>Socialists in an attempt to defeat the candidate who headed the Communist
>list succeeded in giving the Socialist list just enough votes to elect a
>vehemently anti-Communist Socialist.
>
>If you must use list PR my preferred type of list is the 'loose' list. A
>voter can only vote for one party list but can vary the order of
>candidates on that list ( for example in say an 8 member district the
>voter votes for one list and up to 4 candidates on that list. The votes
>for the party lists are used to allocate the seats between parties and the
>votes for the candidates to determine who on the list is elected).
>
>Alternatively you could always use STV where votes only count for the
>candidates you vote for, not for candidates of the same party who you
>don't like and didn't vote for.
>
>David Gamble
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