[EM] How to vote in Approval

[Dave Ketchum]

On Tue, 26 Mar 2002 07:47:12 +0000 MIKE OSSIPOFF wrote:

 > Demorep wrote:
 >
 > Mr. Ketchum wrote in part-
 >
 > Trying to be simple can be deceptive. Approval is easy to count,
 > and sounds easy to vote until you have a ballot in your hands with a list
 > of 4 lemons and need to decide how many of them you want to call 
"approved".
 > ---
 > D- Approve NONE so that NONE get elected.

They are all lemons, to disapprove of, but there is more rot in some so I 
want to help make sure those lose.

Also, there are various meanings of "NONE".  "NOTA", which is used some 
places, can be either:
      An actual vote for NOTA as better than any of the live candidates.
      An embarrassment to the politicians while leaving the election to 
the other voters.
 >
 > I reply:
 >
 > Yes, don't vote for lemons. If some lemons are sourer than others,
 > they're still all sour. A lesser-evil is still an evil.

As I said above, it can matter.  Try actually destroying the country vs 
getting a god start on that but leaving office with the country still in 
recoverable status.
 >
 > I claim that, in our public political elections, there are always
 > unacceptable but winnable candidates, and under those conditions,
 > one's best Approval strategy is to vote for all of the acceptable
 > candidates, and not for any of the unacceptable candidates.
 >
 > Under those conditions in a Plurality election, vote for whichever
 > acceptable candidate is most likely to be able to be helped by you
 > to prevent an unacceptable candidate from winning.
 >
 > Note how much simpler it is in Approval.
 >
 > What if all the candidates are unacceptable? Don't vote for any
 > of them. The pitifully minimal gain from voting for the less
 > disgusting one(s) isn't worth it. Don't validate that "choice" by
 > voting among those candidates.
 >
 > If there are no absolutely unacceptable candidates, then strategy
 > isn't so simple. But, if we have some sort of winnability information,
 > as we do in our political elections, then if you'd vote for a lesser-
 > evil in Plurality, vote for him in Approval too, but also vote for
 > everyone whom you like better, including your favorite.
 >
 > Of course if there are unacceptable candidates, but they aren't
 > winnable, then the above paragraph applies there too.
 >
 > What follows is for elections where there are no winnable unacceptable
 > candidates:
 >
 > If there's no winnability information, that's called a 0-info
 > election, and your best Approval strategy in public elections is
 > to vote for all the candidates whose merit for you is above the
 > mean.
 >
 > By the way, mathematical strategy has been discussed for when
 > there's winnability information ("probability-info"):
 >
 > Preliminary definitions:
 >
 > Ui is the utility (worth) to you of candidate i.
 >
 > Pij is the probability that, if there's a tie for 1st place, it
 > will be between i & j.
 >
 > The strategic value of candidate i is:
 >
 > The sum, over all j (j not equal to i) of Pij(Ui-Uj)

With my voter hat on I am unable to calculate the inputs to those formulas.
 >
 > In Approval, vote for all the candidates whose strategic value is
 > greater than zero. In Plurality, vote for the candidate with highest
 > strategic value.
 >
 > Someone pointed out that it's a fair approximation, when one doesn't
 > have more accurate information, to say that Pij is proportional to
 > the square root of the product of i's probability of winning and
 > j's probability of winning. As an approximation one could say that
 > the probability that i will be in a tie for 1st place if there is
 > one is proportional to the square root of i's probability of winning.
 > For Pij, multiply those tie-probabilities of i & j.
 >
 > The purpose of that is that it might be easier to estimate the
 > candidates' probabilities of winning than it is to estimate the
 > probability that i & j will be in a tie for 1st place if there is one.
 >
 > Derivation of that approximate way of estimating can be found
 > at http://www.barnsdle.demon.co.uk/vote/sing  at the Approval strategy
 > page. In fact the other Approval strategy statements that I've made
 > here are justified at that website. It needs to be updated. For instance,
 > I sometimes used "frontrunner probability" interchangeably with
 > "tie probability", and I haven't corrected that error at that website
 > yet.
 >
Summary:
      I can understand the concept of holding Bush and Gore up to the 
light and picking one as better/worse than the other - which is all I need 
for ranked voting (unless it is a system that invites strategy).
      Trying to decide whether I approve of them enough to list them for 
Approval, especially with other candidates involved, is too much of a strain.
-- 
   davek at clarityconnect.com    http://www.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.