Approval Voting has been use successfully in many organizations, but let's not overstate
its merits. Kenneth Arrow proved that no voting system is perfect, and approval
Voting has flaws.for instance, in competitive elections that are hotly contested,
it often leads to bullet voting. Voters typically have a strongly favored candidate.
What's more, if a voter "approves" of as many candidates as he or she wishes, they
may actually contribute to helping a candidate win who is not their strongly favored
candidate. Thus, the campaigns/candidates will ask their supporters to "bullet
vote," that is, vote or "approve" of only one candidate. This means that approval
voting over time devolves into plurality elections, with problems of candidates winning
with less than a majority and "spoiler" candidates swinging the election. This
has been the case in approval voting, and one of the major reasons why is not used
for any public or governmental elections anywhere.
Here is an example where approval
voting gives ridiculous results, but Instant Runoff Voting/alternative vote gives
better results.
Faction 1 is 40% of the electorate and ranks candidates in the
following order (for an IRV election) and also approves of the same three candidates
(for an approval voting election):
1. Jones 2. White 3. Smith
Faction
2 is 35% of the electorate and ranks candidates in the following order (for an IRV
election) and also approves of the same three candidates (for an approval voting
election):
1. Smith, 2. Jones 3. White
Faction 3 is 25% of the electorate
and ranks candidates in the following order (for an IRV election) and also approves
of the same three candidates (for an approval voting election):
1. White
2. Smith 3. Jones
Under IRV, no one has a majority after the first round (Jones
has 40 percent, Smith has 35 percent and White has 25 percent), so White is eliminated,
her votes transfer to Smith (No. 2 choice of White voters), and Smith is elected
60% to 40%. This makes sense: White had little enthusiastic support, then when the
race went to Jones vs. Smith, most of the voters preferred Smith.
But what happens
under Approval Voting? If each of the factions does not bullet vote, but rather approves
of their top two choices, Jones gets 75% of the vote, White gets 65% of the vote,
and Smith gets only 60% of the vote. Even though most voters prefer Smith to Jones,
Jones wins!
Well, when the uproar dies down, what does Smith do in the next election?
He asks his voters to bullet vote, of course. After all, if his enthusiastic supporters
had simply bullet voted last time, he would have had a better chance of winning;
his voters caused Jones to win. This sort of thing is contagious, and before long
everyone asks their supporters to bullet vote, and you simply have a plurality election.
to reiterate, approval voting is not a perfect system. No voting system
is.
Steven Hill
Center for Voting and Democracy