## Friday, June 09, 2006

##### Just the Facts, Ma'am

The Mathematics of Voting Systems.  Criteria listed in order of (generally) decreasing importance.

S
c
h
u
l
z
e
T
i
d
e
m
a
n
C
o
p
e
l
a
n
d
R
a
y
n
a
u
d
B
a
l
d
w
i
n
N
a
n
s
o
n
D
o
d
g
s
o
n
S
i
m
p
s
o
n
B
u
c
k
l
i
n
H
a
r
e
aka
I
R
V
B
o
r
d
a
C
a
r
e
y
C
o
o
m
b
s
Pareto-Optimal YES YES YES YES YES YES YES YES YES YES YES YES YES
Majority YES YES YES YES YES YES YES YES YES YES NO YES NO
Condorcet YES YES YES YES YES YES YES YES NO NO NO NO NO
Monotonic YES YES YES NO NO NO YES YES YES NO YES NO NO
Clone-Independent YES YES NO YES NO NO NO NO NO YES NO NO NO
Mutual majority YES YES YES YES YES YES NO NO YES YES NO NO NO
Smith YES YES YES YES YES YES NO NO NO NO NO NO NO
Reverse-Symmetric YES YES YES NO NO NO NO NO NO NO YES NO NO
Reinforcing NO NO NO NO NO NO NO NO NO NO YES NO NO
Schwartz YES NO NO NO NO NO NO NO NO NO NO NO NO
Nonmanipulable NO NO NO NO NO NO NO NO NO NO NO NO NO

Shamelessly copied (if somewhat improved) from a voting math amateur enthusiast's webpage here.

NOTE: All of the Libertarian Party, the Green Party, and famous political scientist David Hume like IRV.  The only explanation is that they can not do the math, or that the mathematicians have taken no interest in the matter, or have taken an interest, and lack the explanatory powers.