[EM] Open Lists and Closed Lists

Adam Tarr atarr at purdue.edu
Mon Jul 28 20:04:03 PDT 2003


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.


>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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