[EM] Election-Methods Digest, Vol 62, Issue 10

[Raph Frank]

On Sat, Aug 29, 2009 at 2:05 AM, Stephen H.
Sosnick<shsosnick at ucdavis.edu> wrote:
> When summarizing PR-STV, Raph Frank--like everyone else--says, "Each voter
> gets 1 vote ...."  In fact, however, getting 1 vote is a special case.  And,
> unfortunately,  mentioning only that special case gives opponents of
> transferable-vote systems a politically-effective counter-argument.

I am not sure what you mean here.

Under PR-STV, each voter gets exactly 1 vote that can be moved between
candidates in accordance with the rules (and can be split into
fractions too).

> For example, if 3 seats are open, 100 people vote, and each ballot casts v
> votes, then, for election (though perhaps with a tie-break), a candidate
> needs at least 100v/(3+1) votes, that is, needs at least 25v votes--and will
> have them if the candidate is first choice on at least 25 of the 100 ballots
> (or if the candidate is second choice on at least 50 ballots on which a
> slate-mate is first choice, or is first choice on 20 ballots and second
> choice on at least 5 ballots on which an unsuccessful candidate was first
> choice, etc.).

I disagree with that explanation.  If 2 members of a party get 50
votes between them, then each voter's vote gets split into 2 and half
goes to each candidate.

They still have 1 vote.

> (I might add that, if you prefer to refer to the number or proportion of
> votes needed to guarantee election, then, as Jan Kok points out, the phrase
> "at least" in the last sentence should be changed to "more than.")

I think the way I said it is correct.  The quota is the minimum number
of votes needed to guarantee that you are one of the top 5.

> In Davis, California, as in many other American cities, voters elect either
> 2 or 3 members of a 5-member city council every 2 years.  In those
> elections, a voter may vote for as many candidates are there are open seats,
> and the leading vote-getters win.

This isn't PR-STV, it is bloc voting.

> Opponents of the change, including a
> widely-read columnist in the town newspaper, kept saying that adopting
> proportional representation would deprive voters of their second and third
> votes.

That is true.  The shift from bloc voting to PR-STV would result in a
loss of power for the majority, since the whole point is to give
minority representation.

The counter could be that everyone is reduced to 1 vote, so it is still equal.

Also, the voters would have more freedom to choose who to vote for.  I
am not sure if it is a partisan election, but if so, presumably the
parties run a slate of 2 or 3 for each election?

PR-STV would allow the voters to decide which candidate from the party
that gets elected.  It also allows candidates to stand as independents
(this increases loyalty of the councillors to the voters and lessens
party loyalty.)

> To refute this assertion, one needed to explain how a set of ranked ballots
> is converted into a set of winners--and few member of the public would
> listen long enough.  So we lost--and Davis remains a "general-law" city.

Yeah, PR-STV is hard to explain.

> To improve chances in the future, we should (1) refer to "Transferable Vote"
> instead of to "Single Transferable Vote," and (2) arrange--and say--that
> each ranking ballot casts as many votes as the number of open seats (then,
> in cities like Davis, the value of v would alternate between 2 and 3).

Ahh I see what you are aiming for.

Effectively, each voter gets to submit v ranked ballots.

This could make counting pretty hard.

Presumably, if there were 3 seats, you would take each voters top-3
candidates as their first 3 votes?

Transfers could not be accomplished by moving the ballots.

It might end up being easier to either give each voter 3 ballots or
just make 2 extra copies during the counting.

Alternatively, you could just start each ballot with a weight of 3
(which is mathematically equivalent).

> With a Transferable-Vote system, each shareholder's ballot could still cast
> a number of votes equal to the number shares owned times the number of seats
> to be filled, but the shareholder's total vote now would automatically be
> allocated as the shareholder would wish if he or she knew how other
> shareholders are voting.

I think with shareholders, they normally negotiate for that kind of
thing.  However, companies should certainly be allowed to use
transferable vote as its rules.