[EM] Condorcet - let's move ahead

Dave Ketchum davek at clarityconnect.com
Sun Jan 18 10:52:31 PST 2009

Your promotion of IRV discourages for, while its ballots would be valid
Condorcet ballots, its way of counting sometimes fails to award the
deserved winner (even when there is no cycle making the problem more complex).

That the indicated winner could withdraw does not really help, for that
candidate does not necessarily know whether IRV has erred.

Therefore I still wait to hear from others as to whether MAM deserves
backing, though it properly handled your simple cycle example.


On Sat, 17 Jan 2009 19:40:35 -0800 Steve Eppley wrote:
 > Hi,
 > [I'm not subscribed to RangeVoting at yahoogroups.com, so I won't see
 > replies posted only there.]
 > On 1/9/09 Dave Ketchum wrote:
 >> Extended now to EM - I should have started this in both.
 >> On Fri, 09 Jan 2009 15:40:58 -0000 Bruce R. Gilson wrote:
 >>> --- In RangeVoting at yahoogroups.com, Dave Ketchum <davek at ...> wrote:
 >>>> We need to sort thru the possibilities of going with Condorcet.  I
 >>>> claim:
 >>>> Method must be open - starting with the N*N matrix being available
 >>>> to anyone who wants to check and review in detail.
 >>>> If the matrix shows a CW, that CW better get to win.
 >>>> Cycle resolution also better be simple to do.  We need to debate
 >>>> what we document and do here such as basing our work on margins or
 >>>> vote counts.
 >>> Yes. My biggest gripe with Condorcet is that cycle resolution in many
 >>> systems is so complex that it does not seem that a typical voter (as
 >>> opposed to people like us who are personally interested in electoral
 >>> systems) could understand what is being done.
 > -snip-
 > I think there's no need to gripe or fret.  Resolving cycles doesn't need
 > to be complex.  Here are 2 solutions.
 > 1) The "Maximize Affirmed Majorities" voting method (MAM) is an
 > excellent Condorcet method and is very natural.  Here's a simple way to
 > explain how it works and why:
 >      The basis of the majority rule principle is that the more people there
 >      are who think candidate A is better than candidate B, the more likely
 >      it is that A will be better than B for society. (Regardless of whether
 >      they think A is best.)
 >      Since majorities can conflict like "rock paper scissors" (as shown
 > in the
 >      example that follows) the majority rule principle suggests such
 > conflicts
 >      should be resolved in favor of the larger majorities.
 >      Example: Suppose there are 3 candidates: Rock, Paper and Scissors.
 >      Suppose there are 9 voters, who each rank the candidates from best
 >      to worst (top to bottom):
 >         4                3                2
 >         Rock             Scissors         Paper
 >         Scissors         Paper            Rock
 >         Paper            Rock             Scissors
 >      7 voters (a majority) rank Scissors over Paper.
 >      6 voters (a majority) rank Rock over Scissors.
 >      5 voters (a majority) rank Paper over Rock.
 >      By paying attention first to the larger majorities--Scissors over
 > Paper,
 >      then Rock over Scissors--we establish that Scissors finishes over Paper
 >      and then that Rock finishes over Scissors:
 >         Rock
 >         Scissors
 >         Paper
 >      It can be seen at a glance that Rock also finishes over Paper.
 >      The smaller majority who rank Paper over Rock are outweighed.
 >      Since Rock finishes over both Scissors and Paper, we elect Rock.
 > I think that's not too complex. (How did anyone reach the dubious
 > conclusion that beatpaths or clone-proof Schwarz sequential dropping
 > will be easier than MAM to explain?)  I think the only operational
 > concept that will take work to explain is that there is more than one
 > majority when there are more than two alternatives. (Analogous to a
 > round robin tournament, common to all Condorcet methods, and not really
 > hard to explain.)  Most people already know what an order of finish is,
 > and I think most people are familiar enough with orderings that they
 > will recognize the transitive property of orderings when it's presented
 > visually.
 > Jargon terms such as "Condorcet winner," "beats pairwise" and "winning
 > votes" are unnecessary.  Their use may interfere with moving ahead.
 > Top-to-bottom orderings are more intuitive than the left-to-right
 > orientation many other writers use in their examples.  Two common
 > meanings of "top" are "best" and "favorite."  Two common meanings of
 > "bottom" are "worst" and "least favored."  In those contexts, "over"
 > means "better" or "more preferred."  Left-to-right offers no such
 > friendly connotations (except to the "leftist" minority, and the
 > opposite to the "rightist" minority).  Left-to-right becomes even worse
 > when symbols like the "greater than" sign (>) are used, since a lot of
 > people are repelled by math symbols.  Left-to-right rankings may
 > interfere with moving ahead.
 > 2) One could promote the variation of Instant Runoff (IRV) that allows
 > candidates to withdraw from contention after the votes are published.
 > (I'm not suggesting eliminating the secret ballot.  The corresponding
 > voters' identities would not be published.)  The withdrawal option
 > mitigates the spoiling problem of plain IRV.  It reduces incentives for
 > voters to misrepresent preferences (true also for Condorcet methods, but
 > I think not true for Range Voting, Approval or Borda).  I expect
 > IRV+Withdrawal would exhibit a solid Condorcetian tendency to elect
 > within the sincere top cycle, since supporters of spoilers would
 > pressure them to withdraw when needed to defeat their "greater evil."
 > Obviously, its promotion could leverage the efforts of the promoters of
 > plain IRV.  It can even be argued that IRV+Withdrawal satisfies the
 > spirit of the Later No Harm criterion, if people (or courts) care about
 > that.
 > Assuming IRV+Withdrawal were employed by society for many elections, the
 > eventual switch to a Condorcet method like MAM (or MAM+Withdrawal) would
 > either be found to be unnecessary, or would become fairly obvious due to
 > observations of candidates' occasionally ignoring their supporters'
 > pressure to withdraw (or to not withdraw).
 > Best wishes,
 > Steve
   davek at clarityconnect.com    people.clarityconnect.com/webpages3/davek
   Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
             Do to no one what you would not want done to you.
                   If you want peace, work for justice.

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