
Partisan Gerrymandering and the Efficiency Gap - bryanrasmussen
https://papers.ssrn.com/sol3/papers2.cfm?abstract_id=2457468
======
trendia
The problem with the efficiency gap is that relies on voter patterns, but
voter patterns are affected by gerrymandering.

So if you know that your vote is unlikely to affect the outcome, then you
won't vote, which distorts the efficiency gap metric. In other words, it
incentivizes districts that are so partisan that they discourage the
opposition to vote.

In contrast, the compactness metric [0] only relies on census data and ignores
voting patterns, party membership, or other metrics. Though this has
downsides, at the very least it avoids the feedback loop of the efficiency
gap.

[0]
[https://www.washingtonpost.com/news/wonk/wp/2014/06/03/this-...](https://www.washingtonpost.com/news/wonk/wp/2014/06/03/this-
computer-programmer-solved-gerrymandering-in-his-spare-time)

~~~
gingerbread-man
There are factors beyond compactness which merit consideration, the problem
being that neither has been well-defined in a quantitative sense.

States usually point to two kinds of "communities of interest" with regard to
the redistricting process: racial minorities and citizens connected by some
lower political boundary ie. city limits.

A better re-districting algorithm would have to take those factors into
consideration.

~~~
trendia
Let's suppose we want to introduce other factors. We now have to ask:

* who gets to choose the factors?

* when and how can they be changed?

* how do we measure them?

Let's suppose we go with the "community of interest" approach. As you pick and
choose particular communities of interest to include in the algorithm, it
changes the resulting district. This means that the districts resulting from
such an algorithm can be adjusted by adjusting the types of communities. Thus,
a party with great influence over the process will petition to have
communities of interest that it knows will produce districts favorable to it.
This will work for a time, until the opposition party realizes that they _too_
can influence the districts by petitioning for particular communities of
interest.

Then, when the opposition party comes into power, they will _also_ try to get
those communities changed. No factor is immune to this -- even the influence
of racial categories on districts can be chosen and manipulated (and both
parties ARE doing that, including the "good" party).

So, while the algorithms could be "better" than the pure compactness approach
in an ideal world, it would only work if we could 100% prevent the adjustment
of definitions and weights of communities of interest. And given the nature of
politics, I think that will be very unlikely.

~~~
TheCoelacanth
What if instead of worrying about whether the districts are fair, we worried
about making it so that the fairness of the districts doesn't matter?

If we used mixed member proportional representation, the districts could be
draw using any method and we could still be sure that all voters would be
represented fairly.

------
gingerbread-man
The problem with the efficiency gap as a metric is that, even when districts
are drawn by algorithms blind to partisan affiliation, (considering only
geometric compactness, for instance,) often an efficiency gap persists.

"The challenge for House Democrats is that their while their voter coalition
has proved large enough to carry the popular vote in five of the past six
presidential elections, it remains intensely concentrated, mostly in urban
areas. That concentration provides a systematic advantage to Republicans in
the struggle for the House—even before considering the GOP's edge in control
of redistricting after the 2010 census."
([https://www.theatlantic.com/politics/archive/2015/01/the-
gop...](https://www.theatlantic.com/politics/archive/2015/01/the-gops-control-
of-congress-is-only-getting-stronger/431775/))

Gerrymandering is bad, but fair and equal representation is an individual
right, not something to which political parties are entitled.

~~~
maxerickson
_The problem with the efficiency gap as a metric is that, even when districts
are drawn by algorithms blind to partisan affiliation, (considering only
geometric compactness, for instance,) often an efficiency gap persists._

I think that just illustrates that no rule will meet all definitions of fair.

The proposal in the article hand waves it away by suggesting that the
efficiency gap be used as a limiting test on proposed districts rather than
drawing districts so that it is minimized.

------
dane-pgp
It's worth noting that more proportional voting systems tend to be more immune
to gerrymandering.

~~~
talideon
True, very much true, but some are more resistant to others: mixed-member
systems tend to be less resistant, whereas STV tends to be more resistant.

------
hugh4life
Political parties(at least in the US) are themselves a form of gerrymandering.
The issues for which the 2 main parties stand for seem almost arbitrary except
that one party is "of the future" and the other party is "of the past". Yeah
there's some philosophical basis for the positions but they're often post-hoc
to serve certain special interests.

[edit]

I've frankly become slightly sympathetic to non-democratic forms of government
because I feel political parties inherently lead towards forms of treachery.
They will be bought off or will try to invite outsiders as a means to grab
onto power. My ideal political system these days is a meritocratic lottery
system.

~~~
kqr2
Actually a lottery system is not incompatible with democratic principles. In
fact, it was one of the original principles of Athenian democracy:

From
[https://en.wikipedia.org/wiki/Sortition](https://en.wikipedia.org/wiki/Sortition)
:

    
    
      In ancient Athenian democracy, sortition was therefore the 
      traditional and primary method for appointing political 
      officials, and its use was regarded as a principal 
      characteristic of true democracy.

~~~
maxxxxx
That's an interesting approach.Not so easy to implement probably.

~~~
Natsu
There's also the question of who is eligible for the lottery and who
ultimately controls that determination. That form has a strong incentive to
pervert the lottery process, both by choosing who is eligible and by
perverting the draw itself. The latter is probably easier to secure than the
former.

And even philosophically, I tend to doubt there's any widespread agreement on
what makes a good leader to begin with. If anything, we disagree quite
bitterly regarding that.

~~~
maxxxxx
It may end up like jury duty where people will want to get out of it if they
can.

~~~
iainmerrick
Not everyone tries to get out of it. Some people even enjoy doing their civic
duty.

------
elihu
> Second, we compute the efficiency gap for congressional and state house
> plans between 1972 and 2012. Over this period as a whole, the typical plan
> was fairly balanced and neither party enjoyed a systematic advantage. But in
> recent years — and peaking in the 2012 election — plans have exhibited
> steadily larger and more pro-Republican gaps.

I think the way we normally talk about gerrymandering as a tool that one party
uses to gain an electoral advantage over another party is kind of misleading
and may lead us to measure success by the wrong metric.

Another way to thing about gerrymandering is not as a Republican vs Democrat
thing, but an elected officials versus their constituents thing.

To use the US House of Representatives as an example, House members of both
parties want the same thing, which is to get re-elected. Furthermore, they
want to be re-elected by such a wide margin that their job is secure and they
don't have to spend a lot of time and effort campaigning.

The voters, on the other hand, want their elected representatives to be
accountable, and so they want them to be afraid of possibly losing the next
election. Voters want their preferred party/candidate to win, but it's also in
their best interests that elections are close enough that the implicit threat
of withholding their vote is enough to motivate their representative to do
their job well (whatever that means to the voter).

When party A is able to re-arrange their districts so that all their
candidates have safe seats, they usually cram a bunch of party B's supporters
into districts that also give a certain (smaller) number of safe seats to
party B.

If you think of this as a zero-sum game between party A and party B, then
party A wins a certain number of seats and party B loses an equal number.

If you think of this as a game between the voters and their Representatives,
then the Representatives (of both parties, except for the handful in party B
that lose their seats) won because fewer of them have to work to get votes and
the voters lost because they have less influence than they did before.

The efficiency gap seems like a good metric to measure whether party A or
party B is winning, but it's not obvious to me that it's a good metric for
measuring how safe the seats in a given state have become.

The efficiency gap metric would say that 50% of the votes were wasted in a
2-way near-tie for a not-safe seat, but also that 50% of the votes were wasted
in an election for a safe seat if one candidate got 100% and the other got 0%.

I'm not sure how best to measure seat safeness in a way that can distinguish
an unbalanced result due to gerrymandering versus an unbalanced result due to
one candidate running a better campaign than his/her opponent. We can look at
margin-of-victory statistics in many races in many districts and make
generalizations about how there are more safe districts now than some time in
the past, but it's harder to say conclusively (in a way that would persuade a
judge) that one particular district is gerrymandered.

------
travmatt
Most promisingly, this metric was recently used as a basis for voiding the
gerrymandering attempts of Wisconsin Republicans.

~~~
ticviking
Interesting, I'm also curious of the results of this metric in Utah. they seem
to mention it a few times but I didn't see the actual examples.

