[EM] Why the concept of "sincere" votes in Range is flawed.

Jonathan Lundell jlundell at pobox.com
Mon Dec 1 15:30:09 PST 2008

On Nov 27, 2008, at 11:47 AM, Kristofer Munsterhjelm wrote:

> Jonathan Lundell wrote:
>> It's a reason that "(in)sincere" isn't very good terminology for  
>> everyday use; likewise "manipulation". They're fine terms when well- 
>> defined and used in the context of social choice theory, but they  
>> carry a lot of baggage. A voter is, in my view, completely  
>> justified in ignoring the name of the election method ("approval",  
>> for instance) and the instructions (vote in order of preference)  
>> and casting their vote strictly on the basis of how the ballot will  
>> be counted.
>> (Which is why I'm partial to ordinal systems; it seems to me that I  
>> as a voter can pretty easily order candidates without considering  
>> strategy, whereas the decision of where to draw the line for  
>> Approval, or how to assign cardinal values to candidates,  
>> explicitly brings strategy into the picture.)
> For ordinal systems, it's pretty easy to consider what a honest  
> ballot would be, assuming a transitive individual preference. "If A  
> is better than B, A should be higher ranked than B". It's not so  
> obvious for cardinal systems. What do the points in a cardinal  
> system mean? We can get some measure of a honest ballot by  
> transporting an ordinal ballot into a cardinal ballot: if you prefer  
> A to B, A should have a higher score than B. But other than that,  
> what can we do? This seems to be a problem of cardinal systems in  
> general, not just a particular implementation like Range (or  
> Approval, if you consider Approval Range-1).
> Thinking further, it would seem that cardinal systems can solve it  
> in two ways. Either the points are in reference to something  
> external ("how much would I like that X wins in comparison to that  
> nothing changes from status quo"), or it refers to a subjectively  
> defined unit ("how much do I 'like' X" for an individual definition  
> of "like"). I think ratings, as commonly (and intuitively) used, are  
> of the second part, but that leads to problems with the aggregation  
> of the points. If one voter likes many things and another likes only  
> a few, how do you compare the two preferences? Ranking gets around  
> that since it only asks about relative information (though one could  
> argue there's a very weak form of this problem with equal-ranking;  
> how different does your opinion have to be of two candidates before  
> you no longer equal-rank them?).

I don't really see a need for equal-ranking in a single-winner  
election. As a voter, I'm answering the question "if you were  
dictator, of this set of candidates, who would you choose?". I don't  
really need the option of naming two candidates to the same office; if  
I really have no preference between them, I can flip a coin, or choose  
the tallest, or ugliest, or whatever.

> I guess what I'm trying to say is that the problem of discerning a  
> honest vote from a strategic (optimizing) one seems to be inherent  
> to all cardinal methods, because we can't read voters' minds. That  
> is, unless the external comparison can be made part of the ballot  
> itself.

I suggest that the problem is worse than that: that the voters can't  
even read their own minds, in this sense. Suppose that I would have  
ranked Edwards > Obama > Clinton in the recent US primaries. Fine, I  
can make Edwards=100, but I really don't have the foggiest idea what  
it would mean to make Obama=75 as opposed to Obama=50. Do I like  
Edwards "twice as much" as Obama? What can that possibly mean? It  
seems to me that range voting (including approval) immediately reduces  
to a purely strategic exercise. And what I'd prefer to do is to  
eliminate (to the extent possible) the motivation to strategize at all.

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