[EM] Approval vs. IRV

MIKE OSSIPOFF nkklrp at hotmail.com
Thu Dec 1 13:35:04 PST 2011


Someone said that IRV lets you vote more preferences than Approval does. But what good
does that do, if it doesn't count them?

Approval counts every preference that you vote.

Since Approval doesn't let you vote all of your preferences, it doesn't count all of your
preferences. But, unlike IRV, you can choose which of your preferences will be counted. 

You can divide the candidate-set into two parts in any way you choose. You, and only you, choose
among which two sets of candidates your preferences will be counted.

As I've said, our elections have completely unacceptable candidates. Under those conditions, most
methods reduce to Approval anyway. When, in Approval, you approve all of the acceptable candidates
and none of the unacceptable candidates, you're doing all that you'd want to do anyway.
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Yes, Approval has the ABE problem, the co-operation/defection problem.

We've discussed two solutions for that problem that could be used in Approval:

1. Your faction makes it known that they will, from principle, refuse to support some
inadequate alleged "lesser-evil" compromise. The other greater-evil-opposers
including the supporters of that "lesser-evil" will understand
that, if they need the votes of a more principled faction, and aren't going to get their
votes, then they had better approve that faction's candidates if they don't want a greater
evil to win.

Of course, no one who prefers your faction's policies to those of that "lesser-evil" would
have any pragmatic reason to approve the "lesser-evil" but not your faction's candidate.

2. Forrest proposed an ABE solution for RV, which involved calculating the correct fractional
support to give to the other greater-evil-opposing faction.

I'd like to add that, probabilistically, that method can be used in Approval.

In Forrest's example, where C is expected to get 49%, the A voters inform the B voters
that they will give to C 96% of full support in RV, or an RV middle-rating in an MTA-like system.

If the method is Approval, then the A voters tell the B voters that they're going to vote
for B with 96% probability. That will have the same effect as giving B 96% support in RV.

The A voters would invite the B voters to do the same for them, of course.

Unlike solution #1, which is a bit confrontational, Forrest's fractional rating calculation
is quite diplomatic. "We're going to give you 96% support, and we suggest that you do
the same for us, in case it's we who are big enough to beat C with that amount of support.

As for implementation details, an A voter could put write the numerals from 1 to 10 on
identical rectangular pieces of paper, and put them in a bag. Then, twice (with replacement),
draw out a number, to make a completely random two-digit number. 
If that number is less than 96, vote for B.

Or A voters could be advised to cube their street address, or the time of day expressed
in minutes, or the temperature, etc., and multiply by the square root of two, and then
write down the digits that are 3rd and 4th from the right. 

Or A's and B's parties could have websites that use a pseudorandom number generator to
say "Vote for the other candidate" or "Don't vote for the other candidate", when someone
goes to the website and clicks on a button.

That said, though Approval or MTA is incomparably better than Plurality, and would be completely
adequate, I'd prefer, if electorally-attainable, a method that meets LNHa.

Mike Ossipoff

 		 	   		  


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