[EM] Instead of Top 2

[Kristofer Munsterhjelm]

On 04/20/2013 12:09 AM, Forest Simmons wrote:
> Suppose the two methods were IRV and Approval, and that each voter could
> choose which of the two methods to vote on their strategic ballots, and
> then rank the candidates non-strategically as well for the choice
> between the two method winners.
>
> We would learn something about the popularity of the two methods, which
> one chose the final winner the most often, which one elicited the most
> order reversals, etc.
>
> The same experiment could be done with any two methods.

For that matter, the experiment could be done with ordinary runoff to 
check if the voters change their minds between the rounds of the runoff.

The experiment would go like this: first round, the voters vote using 
the two methods in question, and also give a honest preference ordering 
for a virtual runoff. Second round, they vote in the actual runoff 
between the winner candidates (or some complex tiebreak if the winner is 
the same for both methods). Then one compares the preference orderings 
with the runoff results. If the runoff is A vs B, A won, but the 
preference ordering says B should have won, there's your reversal.

And I've mentioned it before, but I suppose I can do so again, since 
we're talking about two-method runoffs :-) From time to time I've 
thought about the idea of having a runoff using a strategy-resistant 
method and a method that provides good results under honesty. This could 
be useful in a society where people have become used to strategizing. If 
they strategize wildly, then the honest method fails but the resistant 
method keeps the result from being too bad; and if they don't, then the 
honest method's candidate wins the runoff and all is good.