Brief Replies to Tobin's Letter

Mike Ossipoff dfb at bbs.cruzio.com
Tue Jul 9 00:26:30 PDT 1996

```

This is just a brief note, to reply to some of the
things in Tobin's letter. Tobin brings up a number of
new issues, arguments & suggestions, and I'll reply
tomorrow to anything I might miss in this brief reply

With Condorcet's anti-order-reversal strategy, the object isn't
to punish order-reversal, but rather to deter it. It sounds like
the same thing, but it isn't. Because if it's successfully deterred,
it won't have to be punished, because it won't happen--precisely
because it obviously would be punished if it did take place.

It's true that the Clinton voters don't have a strategyk
against order-reversal that ensures that Clinton will win
even if order-reversal happens. But that isn't a fair
thing to say, because no method has a strategy that would
ensure victory no matter what under conditions like that.
Certainly not IRO or Copeland or Regular Champion--or
any method.

***

You mentioned that Smith//Random doesn't tempt order-reversal
because it only has a 1/3 chance of successs in a 3-candidate
race.

But the thing is that order-reversal isn't the real problem
anyway in pairwise methods: The real problem is trunctation.
Order-reversal on a scale sufficient to change the election
result is improbable in a public election, especially considering
that the intended victims would be sure to hear about it in
it's so well deterred in Condorcet.

And in every rank-balloting election that I've conducted or
participated in, there's been much sincere truncation. That's
the problem. Smith//Random does nothing about that. In
never let truncation gain election for someone over whom
a majority have ranked the Condorceet winner. Truncation
isn't a problem in Condorcet, but it's a big problem in
every other pairwise method.

You said that there's only a 1/3 chance that the order-reversers'
candidate would win in the random choice of Smith//Random. But
there's also only a 1/3 chance that the order-reversal would
result in the election of someone whom the order-reversers like
less than the candidate from whom they're trying to steal victory.

Since there's not a thing that anyone can do to thwart the
order-reeversal in Smith//Random, except for the Nader voters
to rank  Clinton in 1st place, or for the Clinton voters to
use a probabilistic strategy to make sure that no one knows
which extreme will beat the other, and since there's only a 1/3
chance that order-reversal in Smith//Random will backfire in
a 3-candidate race, I say that order-reversal is less well-deterred
in Smith//Random than in Condorcet.

***

Mike Ossipoff

--

```