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More surprising summability results

KM
Kristofer Munsterhjelm
Fri, Jan 26, 2024 1:19 PM

A few days ago, I wrote a program that was intended to determine the
minimum number of values requires to tell disjoint winner sets apart,
and I decided to test it with the Condorcet winner sets - i.e. determine
how many values would be required for a summary that tells apart
elections where X is the CW and Y is the CW, for every pair X and Y.

And I couldn't get it to work because it was returning results
suggesting that the number of dimensions required is much lower than the
n^2 I was expecting.

But then I thought a bit about it and I realized there does exist an
O(n) summary that can be used to create a method that passes the
Condorcet criterion... as long as you give up neutrality.

It's so obvious in retrospect, but it was very surprising to me before
the fact. Can you see how it would be done?

-km

A few days ago, I wrote a program that was intended to determine the minimum number of values requires to tell disjoint winner sets apart, and I decided to test it with the Condorcet winner sets - i.e. determine how many values would be required for a summary that tells apart elections where X is the CW and Y is the CW, for every pair X and Y. And I couldn't get it to work because it was returning results suggesting that the number of dimensions required is much lower than the n^2 I was expecting. But then I thought a bit about it and I realized there does exist an O(n) summary that can be used to create a method that passes the Condorcet criterion... *as long as you give up neutrality*. It's so obvious in retrospect, but it was very surprising to me before the fact. Can you see how it would be done? -km
KM
Kristofer Munsterhjelm
Mon, Feb 12, 2024 8:19 PM

On 2024-01-26 14:19, Kristofer Munsterhjelm wrote:

But then I thought a bit about it and I realized there does exist an
O(n) summary that can be used to create a method that passes the
Condorcet criterion... as long as you give up neutrality.

It's so obvious in retrospect, but it was very surprising to me before
the fact. Can you see how it would be done?

Whoops, I have to retract this. The results didn't show what I thought
they'd show, and thus I can't prove O(n) Condorcet -- only O(n)
Condorcet loser (which is easy).

(I then proceeded to trick myself into thinking it was obvious :-)

-km

On 2024-01-26 14:19, Kristofer Munsterhjelm wrote: > But then I thought a bit about it and I realized there does exist an > O(n) summary that can be used to create a method that passes the > Condorcet criterion... *as long as you give up neutrality*. > > It's so obvious in retrospect, but it was very surprising to me before > the fact. Can you see how it would be done? Whoops, I have to retract this. The results didn't show what I thought they'd show, and thus I can't prove O(n) Condorcet -- only O(n) Condorcet loser (which is easy). (I then proceeded to trick myself into thinking it was obvious :-) -km