SR - On Preference Voting
tmcd at austin.ibm.com
Wed Mar 24 18:13:12 PST 1999
[Editors of The Lion's Tale: This is the article I promised.
Unfortunately, I don't have your addresses to hand, so I have to send
it to the list. At least I may get feedback on this. Text in *...*
is in italics.]
Daniel de Lincoln / Tim McDaniel
tmcd at crl.com (backup: tmcd at austin.ibm.com)
Preference voting is a good method for voting on multiple choices, and
it's simple for the voters. Choose the item you want the most to win,
and mark it #1. Find your next choice and mark it #2. Keep going
until you've voted for everything that you might want to win, and then
stop. Don't vote for choices you don't want to win.
Below, I cover the topic "bottom-up", from the details to the big
picture. I describe the vote-counting procedure, the advantages of
preference voting, and how voters should vote. My example is a
hypothetical longship company that's voting on what color sail they
want to buy from a catalog.
HOW THE VOTING WORKS
This procedure is taken from the procedures of the World Science
Fiction Society, which selects the site for the annual World SF
Convention and the "Hugo Awards" using preference voting. Their
constitution is at URL http://www.aussiecon3.worldcon.org/const.html
-- see section 3.11.
For the Hugo Awards, there's a nomination round. Any member can
nominate up to five items. The top five or six nomination-getters are
put on the voting ballot. (For convention site selection, there are
about 1 to 4 bidders.)
Every ballot has some number of candidates, and voters mark them 1, 2,
3, et cetera, in order of preference. Voters don't have to vote for
all of the candidates.
The WSFS counting rule: "Votes shall first be tallied by the voter's
first choices. If no majority is then obtained, the nominee who
places last in the initial tallying shall be eliminated and the
ballots listing it as first choice shall be redistributed on the basis
of those ballots' second choices. This process shall be repeated
until a majority-vote winner is obtained."
Suppose my color choices were: #1, diaper; #2, hot pink; everything
else blank. In the first round of counting, diaper-colored happens to
get the fewest number of first-place votes, so it is eliminated (no
pun intended). My #1 choice will now be ignored. On the second
round, my vote is counted as being for hot pink. Son of a gun: now
that diaper's been washed out, hot pink now happens to get the fewest
votes, so it's also dumped. (Intentional.) On the third round, I
have no indicated choices left, so my vote doesn't go to anything.
(There's one detail I don't want to get into: the Worldcon procedures
always have a "None of the Above" candidate. It gets votes just like
any other candidate. If the final proposed winner can't beat None of
the Above mano-a-mano, there's no winner. This rarely happens.)
If you have only two choices, you might as well use normal voting.
The problem is when you have more than two choices.
Advantage 1: No runoffs. Normal voting doesn't handle it well if
nobody gets a majority on the first round. Usually in the US, the top
two or three vote-getters have a run-off election, and the one who
gets the most votes in the runoff wins. This means having to go to
the effort of running another election.
In preference voting, there's only one balloting. The preferences
handle the runoffs so you don't have to vote again.
Advantage 2: A normal-voting winner may not ever have a majority. Say
there's a three-way runoff, with 34% for purple plaid, 33% for white,
33% for tan. Even if the voters for white and tan hate and despise
purple plaid, purple plaid it is.
In the UK, it's been "first past the post": whoever gets the most
votes wins, majority or not. No runoffs, true, but the winner
sometimes never has a majority.
Advantage 3: Unlike normal ballots, voters don't worry about throwing
away their votes. There's little perceived value in voting for
third-party candidates in the US or UK, because they'll never win, so
you ought to vote for the least objectionable of the two major
candidates, so the third-party votes don't get votes, so they'll never
win, ... It's a vicious circle.
In preference voting, you don't throw away your vote. If you think
hot pink is the best, go ahead and vote for it. If it gets eliminated
early, you'll just get your next choice.
Advantage 4: "Vote splitting" isn't a problem. In normal voting, two
similar candidates tend to drag each other down -- they split the same
pool of voters. Suppose the longship company has choices of red,
teal, and turquoise. Suppose they do a normal vote with "first past
the post" and the counts are 27 for red, 26 for teal, 25 for
turquoise. Light blue colors almost get a 2/3 majority. If there'd
been just one, it'd have won handily. Instead they split the vote and
Preference voting doesn't have the "vote splitting" problem. In a
similar vote, turquoise will get eliminated first, but probably its
votes put teal as #2, so teal gets the votes it deserves.
Advantage 5: It favors candidates with broad support. A controversial
choice may get some #1 choices and nothing else. As other candidates
are eliminated, the controversial choice doesn't pick up support and
may get killed off. A candidate that most people can live with tends
to get a mix of #1, #2, #3, and #4 votes. It may come from behind and
win. A voting system that penalizes controversial choices is a good
one to me!
HOW TO VOTE
This is just a repeat of the first paragraph. Just go ahead and vote
your heart. Decide which choice is the very best choice, and mark it
as #1. Decide what's the second-best and mark it #2. Continue for
every choice you approve of.
Don't vote for things you don't want to win. Even if there's a "None
of the Above" choice and you rank something below it, your vote may
contribute to your undesired choice.
Don't worry about throwing away your single vote. Don't worry about
vote-splitting. If you like two choices about the same, rank them
near each other. If your first choice gets dropped, your further
choices still count.
(It's not much extra effort for the vote counters. You need some data
entry and a simple computer program, or some vote-counting volunteers
with their favorite pizza and beer on a Sunday, or both. It's
certainly less effort than doing a runoff!)
I think that preference voting is the way to go, because of the ease
of voting, the ability to give multiple choices, and the disfavoring
of controversial candidates. I think that there should be a
nomination phase. I think that a committee should count the
nominations and take the highest 5-10 candidates that seem likely to
be registerable via the College of Arms. There should then be a
Go to http://lists.ansteorra.org/lists.html to perform mailing list tasks.
More information about the Southern