[EM] More on Gerrymander prevention

[Michael Rouse]

----- Original Message -----
From: "Adam Tarr" <atarr at ecn.purdue.edu>
To: <election-methods-list at eskimo.com>
Sent: Friday, March 22, 2002 7:55 AM
Subject: Re: [EM] More on Gerrymander prevention


> Michael wrote:
>
> >Draw a line between the population centroid and the
> >voting centroid (or population median and voting median), and continue
until
> >you have the number of districts you want. That way, roughly equal voters
> >and residents would be in each district.
>
> As you implied before, this could easily end up slicing population centers
and
> producing bizzare, sliver-shaped districts.  Also, the population/voter
equality
> in this approach is by no means guaranteed... it could in fact end up
pretty
> radically skewed just depending on the angle between the two.  Imagine
putting
> San Antonio on one side of the line and Houston/Dallas on the other, to
pick an
> easy example.

The problem with sliver-shaped districts is definitely there. On the other
hand, compared to some of the gerrymandered monstrosities that certain
redistricting boards have come up with, this might be less of a problem than
it seems. I wish there was a program that would allow us to play with
various methods of apportionment and compactness -- one where you could
calculate medians, centroids, moments of inertia, perimeter measures, etc.
and apply them to real data -- that way you could determine how common such
problems would be and what the best method would be.

I definitely like the idea of automated districting though, one where there
is a clear and precise way of comparing two or more plans together and
chosing a winner. If there were some clear standard, we could (as others
have suggested) solicit plans not only from computer models and the parties
involved, but from ordinary citizens, and then choose the best one. Heck,
you could have a distributed-processing program like seti at home
(gerrymander at home? redistrict at home?) so that trillions of different options
could be tested (complete with cool screensavers) and the best ones
forwarded to the redistricting boards. If they were obligated by law to
choose the plan that scores the best by some standard method, computer geeks
(of which I'm a proud member) could keep the politicians honest.

Michael Rouse
mrouse at internetcds.com