STV is not house-monotonous!

[Markus Schulze]

Dear Herman,

even if you use the Hare Quota, STV violates
house-monotonicity.

Example:

   28 voters vote A > C > B > D.
   40 voters vote B > A > C > D.
   32 voters vote C > A > B > D.
   80 voters vote D > A > C > B.

****

Hare Quota and two seats => Quota=90.

First round:
  A=28
  B=40
  C=32
  D=80

Candidate A is eliminated. The eliminated
candidate's votes are transfered to their
second choice: C.

Second round:
  A=0
  B=40
  C=60
  D=80

Candidate B is eliminated. The eliminated
candidate's votes are transfered to their
next choice: C.

Second round:
  A=0
  B=0
  C=100
  D=80

Thus: The candidates C and D are elected.

****

Hare Quota and three seats => Quota=60.

First round:
  A=28
  B=40
  C=32
  D=80

The surplus (20 votes) of candidate D is
transfered to the voters' next choice: A.

Second round:
  A=48
  B=40
  C=32
  D=60

Candidate C is eliminated. The eliminated
candidate's votes are transfered to their
next choice: A.

Second round:
  A=80
  B=40
  C=0
  D=60

Thus: The candidates A, B, and D are elected.

Summary: STV violates house-monotonicity
independently on whether you use the Hare Quota
or the Droop Quota.

Markus Schulze