[EM] U/P voting: new name for simple 3-level method.

Jameson Quinn jameson.quinn at gmail.com
Tue Sep 13 10:28:31 PDT 2016

One of the design goals for this system is to minimize the gap in terms of
voting power between a naive vote and a strategic one. I think that it does
a reasonable job at that; most voters' naive vote will be basically
strategically optimal.

Think of a few realistic voter types:
Major Partisan: One major party is good, the other is bad. Naively, will
upvote the good one, and downvote the bad one.
Minor Partisan: One extreme of left-right spectrum is good, the other is
bad. Naively will upvote a minor party on the good side, downvote major and
minor parties on the bad side.
Status Quo: One major party is good, the other one is OK. Minor parties are
scary. Naturally will upvote one major party, and possibly downvote any
minor parties that look as if they might win.
Anti-establishment: Opposite of status quo. Will upvote a minor party or
two, downvote both major parties.

These naive votes will be strategically optimal in the following cases:

- For any majority coalition of Major and Minor partisans plus status quo
leaners from one side of the spectrum. Also for the minority on the other
side in that case, if they prefer the winning opponent over the non-winning
opponents, which is at least as likely as not.
- For the status quo voters if they thereby manage to disqualify a minor
party candidate who would have won.
- Ditto, for the anti-establishment voters.

They will be non-optimal for:
-people on the losing ideological side, who perhaps should have preferred
the most centrist candidate from the winning side. Note that this is
unstrategic for lack of upvotes, not for lack of downvotes.
-Status quo voters, when their less-preferred major candidate wins, AND
their preferred candidate was not disqualified, AND there are significant
numbers of anti-establishment voters to balance out the status quo ones,
AND they could strategically betray without provoking retaliation from the
other part of the status quo voters. In this case, they're insufficiently
downvoting, as Toby worries about. But all of those conditions make the
scenario sufficiently improbable and also sufficiently low-payoff for the
voters in question that I don't think it matters. And even in this case,
the system is arguably getting the socially-right answer, it's just not
strategically stable.

So I think the middle default will not lead to significant strategic
regret. Voters will usually not have reasons to criticize the system, even
if they don't like the outcome.

2016-09-13 12:19 GMT-04:00 'Toby Pereira' via The Center for Election
Science <electionscience at googlegroups.com>:

> There is also the potential problem - as Chris Benham mentioned previously
> - that the default vote is not the bottom rating. Arguably most people who
> know how the system works would simply bottom rate candidates as their
> default move if they aren't actively positively inclined towards them.
> Others who aren't as familiar with the inner workings might not do this, so
> arguably it makes it a bit of a two-tier system for voters. And that could
> be seen as a failure of simplicity.
> On Tuesday, 13 September 2016 02:38:04 UTC+1, Jameson Quinn wrote:
>> Here's a new proposed variant of U/P with a simple default:
>> Voters may rate each candidate as "unacceptable" (downvote), "preferred"
>> (upvote), or "acceptable" (neither). Default is neither.
>> Any candidate downvoted by most, or with fewer than half the max amount
>> of upvotes, is disqualified, unless that would disqualify everyone. The
>> winner is the remaining candidate with the most upvotes.
>> The "fewer than half the max" rule prevents dark-horse winners, without
>> resorting to strange defaults. It has no effect on a two-way chicken
>> dilemma. Though in theory it could affect an evenly-balanced three-way
>> chicken dilemma (in a four-way race), I think there's a negligible chance
>> that such a scenario would be so balanced.
>> I know that Chris doesn't like this method's violation of "irrelevant
>> ballots". Myself, I think that no voters are irrelevant; even if they don't
>> express an opinion between the two frontrunners, they may have one. (True,
>> they may not; but that's not the first assumption I'd make.)
>> --
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