[EM] Range voting, zero-info strategy simulation

[Abd ul-Rahman Lomax]

At 04:42 PM 10/30/2006, Kevin Venzke wrote:
>I wrote a simulation to measure the utility of zero-info Approval
>strategy in zero-info Range elections.

Range Voting is designed to maximize overall utility to society, not 
*expected utility* for the individual voter. This study seems to 
replicate the common criticism of Range Voting, which is that voters 
may attempt to maximize their personal expected benefit by voting 
strategically, in this case by voting Approval style, with a 
particular strategy:

>These results suggest to me that in the zero-info case, if there are
>thought to be more than about 2 other voters, Range should be voted
>as in Approval.

This is utterly unsurprising. Venzke has simply confirmed the 
obvious. If you goal is to maximize your own *expected* satisfaction, 
and you don't value the collective satisfaction of the society, only 
your own, in a very narrow sense, the optimum strategy is Approval: i.e.,

>D. Zero-info Approval strategy. The voter gives a 10 to every candidate
>at least as good as the average value of all candidates, and gives a
>0 to the others.

This is truly zero-info strategy. You don't have to have the foggiest 
notion of what everyone else thinks about the candidates. Useful to 
people who've been living in ... gosh, can't think of any place where 
media don't exist. Perhaps you have been on a round-the-world cruise 
on a balsa wood boat and your radio broke down.

This imaginary voter has somehow managed to determine values for the 
candidates, *all of them*, while remaining utterly innocent of how 
everyone else feels. If the election of one of the candidates would 
cause a revolution, he hasn't got the foggiest idea. I find this 
assumption internally contradictory.

It is thus a bit like the assumption that voters will vote 
strategically because (1) their sincere preference is A slightly 
preferred to B, and (2) they want A to win so much that they will 
distort the expression of their true preferences in order to defeat 
B. They both don't care much and care very much at the same time. And 
it is precisely this thinking which is behind this most common 
assertion that Range is "vulnerable to" or "encourages" strategic voting.

Of course, the statement that the voter "should" vote Approval was 
made without stating the criteria which would determine how voters 
"should" vote.

A Range election is designed to maximize collective value. If voters 
want to generate the greatest good for the greatest number, they will 
sincerely express what the election of each candidate means to 
*them*. If they, instead, effectively lie to the system in order to 
gain some expected extra personal benefit, they may gain a small 
increase in *expected* value, but with two costs: (1) they may lose 
value if their insincere vote results in the loss of their second 
favorite, for example, because they devalued this candidate in order 
to maximize their own favorite candidate's winning. and (2) they risk 
winning at the cost of collective dissatisfaction with the election, 
which can easily harm the "winners," in more than one way. For 
example, the various manipulations which the Republican Party has 
been alleged to have engaged in to distort the vote, over recent 
years, may result in a backlash. Had Bush actually been a "uniter, 
not a divider," this backlash would not have taken place. But I can 
say that I became far more determined, in my own political efforts, 
to ensure the election of Democrats, due to what happened in 2000. It 
was not about losing the election. I felt nothing like this with 
previous Republican victories.

I'd say that the Republican Party won the short-term but, as a 
result, may be losing the long-term. We'll see, of course. I have no 
crystal ball.

(This is not intended to start a political discussion. It is just my 
own point of view, as an example of how winning, at the cost of 
maximizing social satisfaction with the result, can backfire. This 
applies to Democrats who cheat or otherwise take advantage of 
weaknesses in the electoral system as well as to Republicans. And it 
applies in other election environments than that of the U.S.)

I think we need to be very careful about assuming that voters will 
commonly distort their votes in an attempt to manipulate the system 
to produce the election of their favorite. This is tantamount to 
lying to your benefactor about what you want, in order to maximize 
the possibility that your benefactor will give you your favorite 
instead of something almost as satisfactory. Children will do 
this.... and, over time, they learn that is not a great idea.

Then it is argued that such activity on the part of the voter harms 
those who voted sincerely and who were innocent of such distortion. 
Yet when I look at the examples proposed, they show that the sincere 
voters got quite a reasonable result. Just not, necessarily, their 
absolute favorite. And the strategic voters, in this case, also got 
what they want.

The idea that this is a defect in Range is caused by continued and 
often unexamined assumptions that voting systems are supposed to 
elect the pairwise favorite, the Condorcet winner, if one exists. 
This, again, is rooted in an utter neglect of preference strength, 
because the Condorcet winner could be far from being the winner who 
will maximize benefit. I have given examples showing how very bad 
choices can be made by assuming that a whim is equivalent to a strong 
preference.

Since these analysts presume that the pairwise ranking winner should 
win, they think of strategic voting as "bad," and "not to be 
rewarded." It is old thinking. The strategic voter -- which in this 
context means a voter who lies about true preferences in order to 
gain some immediate advantage -- may somewhat increase his immediate 
satisfaction by bullet-voting or Approval style voting, with some 
strategy as was described -- but only when large numbers of other 
voters don't have a strong preference regarding the pairwise election 
in question. Basically, if you care enough to lie to the system, 
well, you care enough to outweigh the mild preferences of other 
voters and your alleged mild preference wasn't.

The paradox behind this, I don't think has been noticed by other 
writers before. I'd appreciate comment on it, particularly from Mr. 
Smith, the Range Voting expert.

I think that real Range data from real Range elections will show that 
this alleged "defect" of Range Voting does not exist, or, more 
accurately, that it does little or no harm.

If the majority allegedly deprived of their allegedly rightful 
victory -- by the election of their second favorite due to "betrayal" 
by the strategic voters -- really care about this, if it is a serious 
loss to them, well, then, it is also true that their alleged mild 
preference was really stronger than stated in all these scenarios.