[EM] Competitive Districting Rule

[raphfrk at netscape.net]

I was reading

http://bolson.org/dist/

about fair redistricting.  He suggests using the distance to the centre 
of the district as the parameter to optimise.

A computer algorithm is then run to try to minimise this parameter 
while keeping all the districts approx equal in size.

I wonder if an additional constraint might be to try to balance the 
vote in each district so as to reduce the number of safe seats.

It would work something like:

The votes for each party is examined from the previous election.  Are 
totals released on a polling booth by polling booth basis?  In not, 
then it would have to be based on a survey or something.

This gives a geographic spread of support for each of the parties.

The constraints that are used for re-districting are then

1)  The districts have reasonably similar populations (say +/- 1%)

2)  The average distance between each person and the centre of their 
district is no more than double the minimum determined when ignoring 3) 
and 4)

3)  Consistant with 1) and 2), pick a district configuration that 
minimises the square of the estimated difference between the top two 
parties in the district

One possible problem with this is that it basically hands all districts 
to the larger party in the previous election.  If a party gets 55% of 
the vote, then a configuration where they have 55% in every district 
minimises 3).

So, adding 4

4)  Randomly order the districts.  When calculating 3), the weighting 
given to each district shall be X% smaller than the weighting given to 
the district that occurs immediately before it in the ranking.  (X 
could be some value, say 33%)

This means that the districts near the start of the list shall be very 
close to 50/50 while the districts near the end of the list will be 
more unbalanced/safe seats.  The net result is that there would be some 
safe seats and some not so safe seats.  However, they would be selected 
at random.