On Jan 14, 2010, at 2:13 AM, Dave Ketchum wrote:
On Jan 13, 2010, at 4:49 AM, Juho wrote:
On Jan 13, 2010, at 9:14 AM, robert bristow-johnson wrote:
it still is a curiosity to me how, historically, some leaders and
proponents of election reform thunked up the idea to have a ranked-
order ballot and then took that good idea and married it to the
IRV protocol. with the 200 year old Condorcet idea in existence,
why would they do that?
1) The basic idea of IRV is in some sense natural. It is like a
street fight. The weakest players are regularly kicked out and they
must give up. I'm not saying that this would lead to good results
but at least this game is understandable to most people. Condorcet
on the other hand is more like a mathematical equation, and the
details of the most complex Condorcet variants may be too much for
most voters. Here I'm not saying that each voter (and not even each
legislator) should understand all the details of their voting
system. The basic Condorcet winner rule is however a simple enough
principle to be explained to all. But it may be that IRV is easier
to market (to the legislators and voters) from this point of view.
When there is a CW in Condorcet, the CW has won in comparison with
each other candidate. While a few may like X or Z enough better to
have given such top ranking, the fact that all the voters together
prefer the CW over each other should count, and does with Condorcet.
Else there is a cycle in Condorcet. Perhaps the following Minimum
Margins Method Condorcet variant should be used to establish
Condorcet's preferability over other methods. Then let other
variants compete with this one before finally deciding which to use.
Minimum Margins Method: Consider the cycle, such as A>B>C>A, and
the margins that create it, such as 60A>30B, 40B>20C, 21C>20A.
Delete the weakest margins as many times as needed to destroy the
cycle - in this case A becoming the CW (note that if one C>A voter
had voted A>C in this election, A would have become CW with no
cycle).
When I see this kind of scenarios I'm always tempted to ask the
question if it is necessary to limit the scope to the top cycle
members or if one can allow also the others win (when the cyclic
opinions in the top cycle are strong). I find also that approach to be
a working solution for many election types (although many have
indicated that they disagree with this).
2) IRV is easier to count manually. Condorcet gets quite tedious to
count manually when the number of candidates and voters goes up.
One can use some tricks and shortcuts to speed up manual Condorcet
counting but IRV probably still beats it from this point of view.
Manual counting was the only way to count for a long time. Nowadays
we have computers and Condorcet tabulation should thus be no
problem at all (at least in places where computers are available).
But this is one reason why IRV has taken an early lead.
When an election district has only one polling place, life is simple.
When the district is a state or city, life is more complex for each
method.
With IRV you first want top ranks from all the ballots in the
district. If there is no majority winner all the ballots for the
worst loser must be scanned for all the polling places for whom
those voters ranked next. Repeat until winner gets decided.
With Condorcet each ballot gets scanned one time and its content
added into an N*N array, with such arrays summed for the whole
district.
Maybe scanning and other ballot checking can be done only once. After
that IRV requires either central counting or central control of the
distributed counting process.
3) Large parties are typically in a key role when electoral reforms
are made. Election method experts within those parties may well
have found out that IRV tends to favour large parties. In addition
to trying to improve the society the best way they can, political
parties and people within them also tend to think that they are the
ones who are right and therefore the society would benefit of just
them being in power and getting more votes and more seats. The
parties and their representatives may also have other more selfish
drivers behind their interest to grab as large share of the power
as possible :-). IRV thus seems to maintain the power of the
current strongest players better than Condorcet does, and that may
mean some bias towards IRV.
4) The problems of different election methods may appear only
later. A superficial understanding of IRV reveals first its
positive features. Like in Burlington the negative features may be
understood only after something negative happens in real elections.
This applies also to Condorcet. On that side one may however live
in the hope that the problems are rare enough and not easy to take
advantage of so that sincere voting and good results would be
dominant. The point is that IRV may be taken into use first (see
other points above and below) without understanding what problems
might emerge later. And once it has been taken into use it may well
stay in use for a long time (electoral reforms are not made every
year, people have already gotten used to the method, having to
change the method could be seen by the society/legislators as a
failure/embarrassment, and people/parties who were elected based on
those rules and are strong in that system may be reluctant to
change the rules).
5) Both IRV and Condorcet have some weak spots that can be
attacked. As you point out the weak spots of IRV may well be worse
than those of Condorcet methods (for most typical use cases in
politics). Different problems may have different weight in
different political environments. For example in countries with
strong two-party tradition and single party government some
Condorcet properties like the possibility of electing candidates
that do not have strong first preference support in the ballots may
work against it (both in the case that one does not want the system
to change and in the case that one wants to renew the system). Also
strategic voting and fraud related problems (like later no harm,
burial, precinct counting) may be seen in different light in
different societies, e.g. in countries where strategic voting is
the norm vs. in ones where sincere voting is the norm. One may thus
have/develop points of view where Condorcet looks worse than IRV (I
guess it could also be worse for some uses in some societies from
some points of view).
So some whose backers tend to rank them top object when they lose
because more other voters rank them below others? I like better
Condorcet's having A win over B when more voters prefer A>B to B>A
without caring which is top ranked by more.
There could be some special cases where you really want first
preference support to exist. For example you could let the soldiers
vote on which country to attack. Eager front row fighters might be
needed. Maybe there are also other such environments (maybe more
realistic too :-).
single party government? If some voters rank B>A and some rank C>A,
A still wins if the total is A>B and A>C. Good to get vote counts
that identify what A is seen as doing well, and what it had better
improve.
I guess many of the fears of Condorcet electing too weak leaders are
based on the assumption that a party/candidate with 20% first
preference support would less capable of forming or leading a
government and a country than a party/candidate with 40% support. In
multiparty countries/governments it is more common to think that
whoever is the biggest of the coalition parties or who is the most
trusted leader among the coalition members may take the lead.
Juho
Juho
P.S. One more reason is that Condorcet promoters seem to be lazier
that IRV promoters :-). Condorcet has made some progress in the
academic circles but not yet in politics.
Agreed, though this is not a reason why IRV deserves to win this race.
Dave Ketchum
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