[EM] Defects in various election systems

[Rob Lanphier]

On Thu, 22 Feb 1996 DEMOREP1 at aol.com wrote:
> Condorcet
> 
> Based on relative comparisons and not absolute approval or disapproval
> (especially for second and later choices).

>From a pragmatic point of view, how useful is information about the 
absolute preferences of the voters?  If we need to pick one and only one 
President, we only need to know which one (and only one) they like best.  
Since voters seldom agree, we *then* need mechanisms for determining 
compromises.

Hence the ranked ballot.  Voters pick *one* top choice, and then can list 
other candidates the can "live with", in order of preference.

Absolute approval/disapproval is irrelevent when we want people to 
*choose* a candidate.  If giving each candidate a grade is what we care 
about, then we should consider approval.

> Circular result ties possible in
> pair comparisons. 

A system that measures voter ambiguity is far superior to one that 
arbitrarily chooses a winner in spite of ambiguity.  Ties are highly 
unlikely in any election method with a sufficient number of voters, 
including Condorcet.

> Approval Voting (AV)
> 
> Based on absolute approval or disapproval. No relative comparisons among
> multiple majority winners.

It also gives disproportionate representation to voters who can't 
distiguish the difference between several candidates.  It is riddled with 
very real strategy problems.

Consider the 1992 election, had it been an approval election.  Voters who
preferred Clinton, but would take Bush in a last ditch effort to keep
Perot out of office stood the danger of helping Bush get elected if they
voted for Bush and Clinton.  Yet they also stood the danger of losing to
Perot if they voted for only Clinton, since there was probably a large
number of people who would have voted for Clinton and Perot to run Bush
out of office.  Perot voters who really didn't like Clinton or Bush would
be forced to vote for neither if Perot is who they truly wanted.  Bush 
voters would have had the same problem.

Ultimately, voters should be expected to choose a candidate, and give 
fallback info if their first choice is not acceptable.  They shouldn't be 
able to choose a wad of candidates and leave it up to everyone else to 
decide.  Nor should voters be forced to use this as a method of 
expressing their preference.

Rob Lanphier
robla at eskimo.com
http://www.eskimo.com/~robla