So Lavabit decided to cut service instead of opening themselves to
unspecified snooping. Thus I had to switch mail providers, and with lots
of real world stuff going on too, I've been quite idle this month.
So let's fix that by showing what I've been thinking about regarding
Condorcet-type Sainte-Lague methods. And since Jameson said that it's
better to write multiple posts instead of one long post on many
subjects, I'll split my long document into parts.
There's strategy, where I noticed strategy. Then there's a description
of a quite complex Condorcet-SL hybrid that *almost* works (very close
to generalizing correctly), and finally some examples of how that method
mitigates the need for strategy in my example.
So, strategy:
---
I have found out that voters may have reason to strategize in
Sainte-Lague not only when there are few seats, and not only when their
honest first preference has no chance of getting a single seat, but also
in other situations. Consider the following example, where all
candidates are parties:
549: pA
102: pM
349: pB
10: pM > pB > pA
If the last ten voters honestly vote for party M, then the outcome is
that A gets six seats, M gets a single seat, and B gets three. But if
the last ten voters compromise for B, we get:
549: pA
102: pM
359: pB
and A gets five seats, M still gets the one, and B gets four. The last
ten voters prefer this to the honest outcome, so they have an incentive
to compromise.
More generally, there's a compromising incentive in ordinary Sainte
Lague, which shouldn't suprprise us since it reduces to Plurality in
the one-seat case. CPO-SL handles the most egregrious cases of these
compromising problems by reducing to Condorcet in the one-seat case and
by also dealing in a Condorcet manner with parties that don't get a
seat, but the problem still exists for parties that get slightly more
than a seat.
----
Election-Methods mailing list - see http://electorama.com/em for list info
