tag:blogger.com,1999:blog-84838185699918298962024-03-16T04:18:23.186-04:00B-DistrictingThe story of writing <a href="http://bdistricting.com/">redistricting software</a> and other thoughts on redistricting.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.comBlogger78125tag:blogger.com,1999:blog-8483818569991829896.post-83009050047195929322021-02-27T09:42:00.001-05:002021-02-27T09:42:38.278-05:00DC and PR<p> Just in case anyone is thinking about statehood, I've decided I should make some hypothetical maps for Washington, D.C. and Puerto Rico. (Someday, in September, when we have data.)</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgYQnX6W2cGsvAwecXgGbeKDxrGw-KNffb2wn-X5INsSjiRONYqosDNpty6BbShZpwVMPute1XcFrYXz4xfae3wSo46z_aqh5DsXK4ZpL5Gv_OoJz-huYrkuaMuzeF_dqNlG9xhf0aWweXW/s1080/DCblocks.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1080" data-original-width="865" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgYQnX6W2cGsvAwecXgGbeKDxrGw-KNffb2wn-X5INsSjiRONYqosDNpty6BbShZpwVMPute1XcFrYXz4xfae3wSo46z_aqh5DsXK4ZpL5Gv_OoJz-huYrkuaMuzeF_dqNlG9xhf0aWweXW/s320/DCblocks.png" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRDEwBeKpnfOPHwpPIrVCPu4buD1n_JNN3vaqD3IeYanUftBYbx6NaXLyfwNNK0p7pNoDdV_YwubCE53SC2bdMR7X1xhLLDwDyE49STtvP87tDGEKTkmH_SqqKwFv2kWDAecIH8pFCslhh/s1920/PRblocks.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="523" data-original-width="1920" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRDEwBeKpnfOPHwpPIrVCPu4buD1n_JNN3vaqD3IeYanUftBYbx6NaXLyfwNNK0p7pNoDdV_YwubCE53SC2bdMR7X1xhLLDwDyE49STtvP87tDGEKTkmH_SqqKwFv2kWDAecIH8pFCslhh/s320/PRblocks.png" width="320" /></a></div><br /><p><br /></p>Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com20tag:blogger.com,1999:blog-8483818569991829896.post-90044288257815415002021-02-12T21:46:00.000-05:002021-02-12T21:46:05.921-05:00Census Delays, BDistricting Well Positioned<p>NPR reports that the US Census Bureau might not release <a href="https://www.npr.org/2021/02/12/965823150/6-month-delay-in-census-redistricting-data-could-throw-elections-into-chaos">redistricting data until September 30,</a> long after the usual dates in February through April, or the previous delayed estimate of July. BDistricting's fully automated approach should be just fine though. In a crunch we can rent a bunch of cloud servers and have good results for any state as little as a day after the data is available.</p>Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com9tag:blogger.com,1999:blog-8483818569991829896.post-68418376932611847832021-01-18T09:13:00.000-05:002021-01-18T09:13:12.457-05:00Redistricters, start your engines!<p>The 2020 Census data for redistricting is <a href="https://www.census.gov/newsroom/press-releases/2021/2020-census-geographic-products.html">immanent starting around 2021-01-19</a>, but we don't have official reapportionment yet! The last report from the Census bureau was "<a href="https://www.census.gov/newsroom/press-releases/2020/2020-census-update-apportionment.html">early 2021, as close to the statutory deadline as possible</a>". If they don't have proper apportionment out by the 19th, I guess I'll start my redistricting engine based on <a href="https://www.esri.com/arcgis-blog/products/esri-demographics/state-government/reapportionment-projections/">estimates</a> (or <a href="https://www.prb.org/u-s-house-seats-are-shifting-south-and-west-based-on-population-changes/">this estimate</a>, or others, or some consensus I put together).</p>Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com4tag:blogger.com,1999:blog-8483818569991829896.post-21312723722915776962019-06-29T12:39:00.001-04:002019-06-29T12:39:55.186-04:00SCOTUS on North Carolina and Maryland; 2019-06-27In a <a href="https://www.supremecourt.gov/opinions/18pdf/18-422_9ol1.pdf">decision released Thursday, June 27, 2019,</a> Roberts (with Kavanaugh, Gorsuch, Alito, and Thomas) wrote 32 pages amounting to, 'Gerrymandering is bad, but aw shucks there is nothing we can do'. Kagan (with Breyer, Ginsburg, and Sotomayor), rebutted in equal length 'there absolutely is something we can do and we really should have'.<br />
<br />
One of the innovations in these court challenges was the "ensemble" method of producing thousands of plausible maps and doing statistics across likely outcomes of those maps. Kagan found that this demonstrated "the State’s map was an out-out-out-outlier" in the case of North Carolina's map which was worse than all 3000 other proposed maps it was compared to. Roberts mocked this claiming, "Judges not only have to pick the winner—they have to beat the point spread." Roberts at other points wanted to avoid such 'hypotheticals', but Kagan found that "... the same technologies and data that today facilitate extreme partisan gerrymanders also enable courts to discover them, ..." Kagan isn't afraid of technology, it's not some weird magic black box to her. It's a tool, and it's not some weird hypothetical, it's a tool actually used to create real and effective gerrymanders, and the same tools can analyze and pick apart those gerrymanders.<br />
<br />
With great handwringing, Roberts repeatedly claimed that there was no solid rule on which to base a decision or decree a change. Kagan responds with a long list of citations of Supreme Court and other Federal Court decisions that found rules and made decrees.<br />
<br />
Roberts implicitly suggested that Congress and State Legislatures could make laws creating such rules. He cited a list of bills relating to redistricting rules to which Kagan responded, "what all these <i>bills</i> have in common is that they are not <i>laws</i>. The politicians who benefit from partisan gerrymandering are unlikely to change partisan gerrymandering. And because those politicians maintain themselves in office through partisan gerrymandering, the chances for legislative reform are slight." (Emphasis Kagan's)<br />
<br />
Kagan doesn't think we should wait for ballot initiatives either: "Fewer than half the States offer voters an opportunity to put initiatives to direct vote; in all the rest (including North Carolina and Maryland), voters are dependent on legislators to make electoral changes (which for all the reasons already given, they are unlikely to do)."<br />
<br />
And on independent commissions, "Some Members of the majority, of course, once thought such initiatives unconstitutional. See Arizona State Legislature, 576 U. S., at ___ (ROBERTS, C. J., dissenting)"<br />
<div>
<br /></div>
<div>
———</div>
<div>
<br /></div>
<h3>
Looking Forward</h3>
<div>
Should we have Congress make a law restricting gerrymandering nationwide? Absolutely. We should have a new Voting Rights Act that ensures a fair process in every state. We should also have a Congress that will pass it and a President who will sign it.</div>
<div>
<br /></div>
<div>
We should also have a Court that will do their job. For over two hundred years the Supreme Court has been a check against bad laws. Gerrymandered district maps passed by state legislatures are bad laws. Instead of using their encyclopedic knowledge to write 32 pages of "we don't wanna" they should have done their duty to the Constitution and the people of the United States of America and defended our democracy.</div>
Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com8tag:blogger.com,1999:blog-8483818569991829896.post-34923403524889834842019-03-30T09:55:00.000-04:002019-03-30T09:55:00.407-04:00"ALURE" Blocky Recursive DistrictsAnother algorithmic redistricting implementation! <a href="https://www.facebook.com/ALURE.Redistricting/">"ALURE" (ALgorithmic Universal Redistricting Engine)</a> (their only web presence seems to be that facebook page) looks like another recursive split algorithm like "shortest splitline", but keeping to north-south and east-west cuts and boxes.<br />
<br />
It makes districts. They're pretty simple. Given the alternative of complex gerrymandered monsters simple sounds like a good feature.<br />
<br />
My usual criticisms of "process" oriented districting applies. Nothing about this process will necessarily produce "good" districts. Its simplicity ignores all existing county and city boundaries which would make it hard to manage. (Something my own software misses too, which I 'm working on for 2020.)Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com6tag:blogger.com,1999:blog-8483818569991829896.post-90877899040668286842019-03-28T12:54:00.003-04:002019-03-28T12:54:17.536-04:00Chris Larson method of automatic redistrictingA new <a href="https://medium.com/@chrismlarson/a-new-redistricting-algorithm-motivations-and-method-1515233fce04">automated redistricting algorithm</a> has appeared with concrete examples for Michigan and Virginia. It sounds like it's doing something like a <a href="https://en.wikipedia.org/wiki/Minimum_cut">minimum cut</a> through the blocks that have lowest population. It winds up doing this in mostly horizontal or vertical lines, based on how the Michigan map looks. It mostly keeps counties together, but when it decides it needs to cut it can make a long cut on a straight-ish line through many counties.<br />
<br />
In the dichotomy of solutions being "fair process" vs "good outcome" this is another "fair process" entry. I like its output subjectively better than the "<a href="https://rangevoting.org/SplitLR.html">shortest splitline</a>" algorithm, and the county-cohesion feature will make it more practical, but I still think there's nothing inherent in its structure that will ensure a "good outcome". I still prefer to start at the end, define what kind of outcome we want, and achieve that by whatever methods happen to work. If we have the right metric, then optimizing to it will be okay. (On the other hand, the last century of industrial best practices point out that picking the right metric is problematic and good process needs to be blended with metrics for actual best outcomes.)<br />
<br />
<a href="https://medium.com/@chrismlarson/a-new-redistricting-algorithm-motivations-and-method-1515233fce04">https://medium.com/@chrismlarson/a-new-redistricting-algorithm-motivations-and-method-1515233fce04</a><br />
<a href="https://github.com/chrismlarson/redistricting">https://github.com/chrismlarson/redistricting</a><br />
<div>
<br /></div>
Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com6tag:blogger.com,1999:blog-8483818569991829896.post-84482304709244338372019-01-08T23:49:00.000-05:002019-01-08T23:49:04.132-05:00Clean Missouri Shoddy ProportionalityMissouri passed the "<a href="https://www.cleanmissouri.org/">Clean Missouri</a>" "<a href="http://www.cleanmissouri.org/wp-content/uploads/2018/04/Packet-048-Petition-Text-copy.pdf">Amendment 1</a>" last November, and among other things it changes how redistricting gets done there.<br />
tl;dr: they did some weird things I think will have messy unintended consequences<br />
<br />
In 2021 they'll appoint a "non-partisan state demographer" who will do the first pass at map drawing. But the law has a pretty strict set of rules to design to.<br />
In order of priority:<br />
<br />
<ol>
<li>Equal Population</li>
<li>No racial bias (or could be read to require VRA style gerrymandering-for-good)</li>
<li>"Partisan fairness and, secondarily, competitiveness". Fairness being: "the
difference between the two parties’ total wasted votes, divided by the total votes cast for the two parties, is
as close to zero as practicable." Furthermore, competitiveness: "simulate elections in which the hypothetical statewide vote shifts by one percent, two percent, three
percent, four percent, and five percent in favor of each party. The vote in each individual district shall be
assumed to shift by the same amount as the statewide vote. The non-partisan state demographer shall
ensure that, in each of these simulated elections, the difference between the two parties’ total wasted votes,
divided by the total votes cast for the two parties, is as close to zero as practicable"</li>
<li>Contiguous</li>
<li>Respect existing political boundaries</li>
<li>Compactness</li>
</ol>
<h2>
Political Fairness and Competitiveness</h2>
<div>
Their "Political Fairness" is what I call proportionality. It's interesting that they come at it from wasted vote, and I think that's probably a good measure, it's just a little inside out and backwards of how I usually frame this. I'd usually say "the party with 60% of the people should get 60% of the seats in the state legislature", but they're saying "the party with 40% of the people shouldn't have proportionally more of their votes wasted in districts they don't win than the other party wastes in districts it doesn't win". This 'efficiency gap' was a big deal in a recent case in Wisconsin that got to the Supreme Court (but SCOTUS declined to accept the efficiency gap as a sufficient measure for determining a gerrymander they'd overrule). It remains to be seen if the efficiency gap is really a good measure or a statistical fad.</div>
<div>
Their measure of "Competitiveness" also comes directly out of recent research into gerrymandering. People have done similar analysis in Wisconsin and Michigan and determined that they disadvantaged party is not only not getting proportional representation but they would have to win huge shifts in the electorate and huge landslides in order to catch up. I'm not sure this specific proscribed simulation is actually a good statistical method though. The law goes as far as describing the statistical model, saying that each district shall be simulated to shift by a specific formula, and I kinda expect we don't yet have the best model for doing those simulations.</div>
<div>
<br /></div>
<h2>
Trying To Predict Unintended Consequences</h2>
<div>
If we're lucky, in the best case, this system will result in a Missouri State Legislature that on average reflects the citizens of that state.</div>
<div>
<br /></div>
<div>
That "on average" is a hedge because I think they'll get a lot of messy districts. By messy I mean non-local, tentacled monsters; the hallmark of gerrymandering. But maybe that doesn't matter? One thing I keep running into around US culture and representative government is that people identify with their place less and less. So, I hear some voices of dissent saying that it's weird to be in a district with some random people over there connected by a squiggly district, but also I hear people not caring about that and just caring about whether they can vote for and elect someone who agrees with their values. If more people can get that, being represented by someone they kinda like, maybe that's a good thing. If the State Legislature more accurately reflects the average of the people in the state, that's a good thing, messy though this way might be.</div>
<div>
<br /></div>
<div>
But it could also lead to 10 years of unmitigated incumbency. Before California moved to an independent redistricting commission, they had a bipartisan gerrymander where everyone had a safe seat and incumbency was rampant. This system could easily produce that. Or it might produce half safe seats and half "competitive" seats designed to be closer to 50/50 between the two major parties. If you're living in a safe seat district, you're stuck with that and your vote (except maybe at the primary) will never really matter.</div>
<div>
<br /></div>
<div>
I'm curious if they'll actually break contiguity or if that will sneak back up to its traditional place next to equal population.</div>
<div>
<br /></div>
<div>
Lastly, with compactness at the bottom of that heap, we can pretty much ignore it.</div>
<h2>
What About Future Laws?</h2>
<div>
I also think it's just kinda fascinating that this oddly specific law passed. <a href="https://www.npr.org/2019/01/08/682979916/missouri-voters-backed-an-anti-gerrymandering-measure-lawmakers-want-to-undo-it">Missouri Republicans are contemplating a try to repeal it</a>, but if they don't it should be a <i>fascinating</i> experiment in democracy. I guess we'll know how it goes some time around 2022 or 2024. I wouldn't recommend following this law as a model, but hey, let's see how it goes?</div>
Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com139tag:blogger.com,1999:blog-8483818569991829896.post-69649630642627749752018-09-02T09:20:00.002-04:002018-09-02T09:20:54.383-04:00What is "Proportional"? Apportionment AlgorithmsI think by “Proportional” we mean a linear interpolation, the number of seats allocated to various populations should scale linearly with those populations.<br />
<br />
I was writing this up in code and ran into some subtleties and wanted to share.<br />
<br />
First, the US House apportionment algorithm is not proportional! It allocates one seat to every state and then approaches linear after that. Wyoming never quite comes back in line.<br />
<br />
Second, integer linear interpolation on many dimensions simultaneously can be subtle. I modified <a href="https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm">Bresenham’s integer linear interpolation algorithm</a> (common in computer graphics) but tried two different ways of applying it in parallel to many lines at once and made a minor bug on my first try, so I want to share what I learned. My first attempt was to cycle through all the groups in descending population order to see if they needed a next apportionment seat; and just repeat this until all the seats were apportioned out. My better algorithm does a pass through all the groups, then re-sorts them based on how far behind the line they are and how much they need a next seat. Repeating these two steps works better: passing through all the groups - maybe allocating, then re-sorting all the groups based on updates.<br />
<br />
The second line below is populations for 4 hypothetical groups or states. For 9 seats there would be 0.009 people per seat if everything were fair.<br />
<br />
<span style="font-family: "courier new" , "courier" , monospace;">target p/s 0.009</span><br />
<span style="font-family: "courier new" , "courier" , monospace;">pops 15 44 368 573</span><br />
<span style="font-family: "courier new" , "courier" , monospace;">house 1 1 3 4</span><br />
<span style="font-family: "courier new" , "courier" , monospace;">house p/s 0.0666667 0.0227273 0.00815217 0.0069808</span><br />
<span style="font-family: "courier new" , "courier" , monospace;">nb 1 0 1 3 5</span><br />
<span style="font-family: "courier new" , "courier" , monospace;">nb 1 p/s 0 0.0227273 0.00815217 0.008726</span><br />
<span style="font-family: "courier new" , "courier" , monospace;">nb 2 0 0 3 6</span><br />
<span style="font-family: "courier new" , "courier" , monospace;">nb 2 p/s 0 0 0.00815217 0.0104712</span><br />
<br />
Above you can see the House algorithm, my algorithm versions 1 and 2. Each pair of lines shows the seat allocations and the “p/s” population/seat. The House algorithm has some large over-representations of tiny groups and resulting under-representation of other groups. My final algorithm avoids this.<br />
<br />
The House algorithm is probably still the right answer for the US House. More broadly I want to figure out a good definition of what is fair for Proportional Representation. In PR one could simply say that a group that is 33% of the population should get 33% of the seats, but if there are 10 seats should they get 3 or 4? That depends on the various sizes of other groups being represented. I want to codify this into good rules for what is fair and ideal, and then do work on practical systems that can as closely as possible achieve this.<br />
<br />
<a href="https://github.com/brianolson/voteutil/blob/master/python/apportion.py">My apportionment code in Python on github</a>Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com10tag:blogger.com,1999:blog-8483818569991829896.post-88027101299433409912018-06-25T11:58:00.000-04:002018-06-25T11:58:25.764-04:00Gil v Whitford decision; 2018-06-18The Supreme Court of the United States (SCOTUS) gave <a href="https://www.supremecourt.gov/opinions/17pdf/16-1161_dc8f.pdf">a 41 page document around political gerrymandering in Wisconsin</a>. Below are my notes.<br />
<br />
<div>
The main decision was a unanimous procedural action to bump the case back down to District Court. A concurring opinion from Kagan, Ginsburg, Breyer, and Sotomayor laid out a road may for the plantiffs to fix their case and come back and try again. I believe there is one more legal challenge not sufficiently pursued in this case.</div>
<h3>
The Procedural Rebuff</h3>
<div>
Chief Justice Roberts, et. al., primarily ruled that the plaintiffs had not sufficiently shown 'standing' for their case. They had to show that they had personally been harmed by the effects of gerrymandering. The plaintiff most cited, who must have done most of the talking during the original case, wasn't from a badly gerrymandered district. Even measuring gerrymandering is problematic and they don't like most of the measures.</div>
<div>
<br /></div>
<div>
The Court is aware of the mediocrity they have contributed to this situation. "Our previous attempts at an answer have left few clear landmarks for addressing the question." (p.8)</div>
<div>
<br /></div>
<div>
What they most wind up looking at is 'dilution of votes'. But, "To the extent the plaintiffs’ alleged harm is the dilution of their votes, that injury is district specific." (p.14) SCOTUS seems to want district by district, 'this one was packed', 'this one was cracked'. They disparage systemic, state-wide statistics, but want to focus on effects on concrete single voters.</div>
<div>
<br /></div>
<div>
The main decision claims that the fix could be small:</div>
<div>
<blockquote class="tr_bq">
"Remedying the individual voter’s harm, therefore, does not necessarily require restructuring all of the State’s legislative districts. It requires revising only such districts as are necessary to reshape the voter’s district—so that the voter may be unpacked or uncracked, as the case may be." (p.16)</blockquote>
</div>
<div>
The concurring decision later suggests getting plaintiffs from every packed or cracked district, so that the result will wind up affecting pretty much all the districts.</div>
<div>
<br /></div>
<div>
On the "Efficiency Gap" measure:</div>
<blockquote class="tr_bq">
"The difficulty for standing purposes is that these calculations are an average measure. They do not address the effect that a gerrymander has on the votes of particular citizens. Partisan-asymmetry metrics such as the efficiency gap measure something else entirely: the effect that a gerrymander has on the fortunes of political parties." (p.20)</blockquote>
<div>
<br /></div>
<div>
7 of 9 members of the court felt that the case still had a chance though, so they bounced it back down to District Court. Thomas and Gorsuch wanted to just close the case and let the gerrymander stand.</div>
<h3>
The Concurring Hope</h3>
<div>
The Kagan, Ginsburg, Breyer, Sotomayor concurring opinion mostly calls out ways to make the anti-gerrymandering case better. They suggest that there's a good First Amendment claim to be made around freedom of association and the ability to effectively coordinate as a political party.</div>
<div>
<blockquote class="tr_bq">
"... a plaintiff presenting such a theory would not need to show that her particular voting district was packed or cracked for standing purposes because that fact would bear no connection to her substantive claim."<br />"... everything about the litigation of that claim—from standing on down to remedy—would be statewide in nature." (p.2)</blockquote>
<div>
The main decision had a few notes, as SCOTUS frequently does, of "not our job" because they want lawmaking to be done by the legislatures and the congress, but this critique notes that,</div>
<blockquote class="tr_bq">
"... only the courts can do anything to remedy the problem, because gerrymanders benefit those who control the political branches." (p.2)</blockquote>
</div>
<div>
<br /></div>
<div>
They cite "Wesberry v. Sanders, 376 U. S. 1, 7 (1964)" for the "one-person, one-vote" principle and how fractionally diluting a vote is bad.</div>
<div>
<br /></div>
<div>
This to me sounds like an endorsement of the rising "ensemble" method of statistically challenging gerrymanders:</div>
<div>
<blockquote class="tr_bq">
"In many partisan gerrymandering cases, that threshold showing will not be hard to make. Among other ways of proving packing or cracking, a plaintiff could produce an alternative map (or set of alternative maps)—comparably consistent with traditional districting principles—under which her vote would carry more weight." (p.3)</blockquote>
</div>
<div>
<br /></div>
<div>
How to get a state wide effect for the state wide problem, more plaintiffs from all the packed and cracked districts:</div>
<blockquote class="tr_bq">
"Assuming that is true, the plaintiffs should have a mass of packing and cracking proof, which they can now also present in district-by-district form to support their standing. In other words, a plaintiff residing in each affected district can show, through an alternative map or other evidence, that packing or cracking indeed occurred there." (p.6)<br />"... with enough plaintiffs joined together—attacking all the packed and cracked districts in a statewide gerrymander—those obligatory revisions could amount to a wholesale restructuring of the State’s districting plan." (p.7)</blockquote>
<div>
<br /></div>
<div>
The main opinion claimed that the intent of the legislature didn't matter (documents were presented about deliberate gerrymandering) only the resulting injury to specific voters. Kagan, et.al., cite "Alabama Legislative Black Caucus v. Alabama" claiming that motive evidence counts and that statewide systemic evidence counts.</div>
<div>
<br /></div>
<div>
Getting back to the First Amendment free-association claim:</div>
<div>
<blockquote class="tr_bq">
"The complaint in such a case is instead that the gerrymander has burdened the ability of like-minded people across the State to affiliate in a political party and carry out that organization’s activities and objects." (p.10)<br />"... nothing in the Court’s opinion prevents the plaintiffs on remand from pursuing an associational claim, or from satisfying the different standing requirement that theory would entail." (p.11)</blockquote>
</div>
<div>
The opinion closes with notes about how gerrymandering is bad and it hurts America and it has gotten a lot worse in the last two decades.</div>
<h3>
One More Thing</h3>
<div>
From the main opinion:</div>
<blockquote class="tr_bq">
"The 99 members of the Assembly are chosen from single districts that must “consist of contiguous territory and be in as compact form as practicable.” §4. " (p.2)</blockquote>
<div>
What if the whole case is really much simpler? I can trivially show that the <a href="https://bdistricting.com/2010/WI_Assembly/">Wisconsin districts are not as compact as practicable</a>. <b>The Legislature of Wisconsin broke Wisconsin's laws</b>. Just as in the <a href="http://blog.bdistricting.com/2018/01/pennsylvania-fair-district-rules.html">recent Pennsylvania case</a>, that's all you need. State court can throw out the gerrymandering.</div>
Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com7tag:blogger.com,1999:blog-8483818569991829896.post-29413217834036367302018-03-09T18:07:00.000-05:002018-03-09T18:07:14.011-05:00Another Gerrymandering GameHere's <a href="http://playgerrymander.com/">a game to practice your gerrymandering by packing and cracking</a>. It starts pretty simple on a 3x3 board making districts of 3 blocks and builds up to a 7x7 board building 7 block districts. I am frequently a completionist on little games like this, but when you get to level 50 it will just keep going forever, so when you get there, congratulations, you won the game.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com4tag:blogger.com,1999:blog-8483818569991829896.post-63923455377612608822018-02-06T14:55:00.000-05:002018-02-06T14:55:40.381-05:00Partisan Outcome of Compact DistrictsI have often been asked what the likely partisan breakdown of my maps would be. I never had the data to do that analysis, but <a href="https://projects.fivethirtyeight.com/redistricting-maps/#algorithmic-compact">FiveThirtyEight got the data and analyzed my maps and 7 other plans for various notions of gerrymandered and fair</a>.<br />
In short, <b>my compact maps are very slightly less Republican and a bit more competitive</b>. I've always believed that on average in the last two districtings Republicans have done more of the gerrymandering and stolen more US House seats than the Democrats have. The difference was smaller than I expected though. The difference is probably smaller than this model can usefully tell us about. All models are wrong, some models are useful, and this model is certainly not destiny but can maybe tell us something useful about the biases in the system.<br />
FiveThirtyEight estimates that the current map has 195 safe Republican seats, 168 safe Democratic seats, and 72 competitive seats; and that this will on average elect 234.4 Republicans and 200.6 Democrats. Actually in 2016 we got 241 Republicans and 194 Democrats. 7 seats out of 435, 1.6% off, not bad.<br />
They estimate that under my compact map that goes to 180 safe Republican seats (-15), 151 safe Democratic seats (-17), and 104 competitive seats (+32); with an expected outcome of 232.2 R and 202.8 D (D +2.2).<br />
That 2.2 seat change looks pretty small, but I want to be optimistic about the <b>32 additional competitive districts</b>. The US may be self-sorting, but while gerrymandering deliberately creates uncompetitive districts on both sides, simply <i>not gerrymandering</i> creates additional competitive districts. I'm not in favor of distorting districts specifically to create competitive districts (which 538 explored and created a whopping 242 competitive districts) but not deliberately creating uncompetitive districts is something I'm solidly behind. Uncompetitive districts make democracy depressing when you know you don't really have any choice, and I want this country to have more democracy.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com4tag:blogger.com,1999:blog-8483818569991829896.post-31387232927440907042018-01-22T16:00:00.001-05:002018-01-22T16:00:22.547-05:00Pennsylvania Fair District RulesIn <a href="http://www.pacourts.us/assets/opinions/Supreme/out/Order%20%20GrantedJurisdiction%20Retained%20%2010339890932033626.pdf?cb=1">a decision handed down on January 22, 2018 by the Pennsylvania Supreme Court</a>, they decreed that gerrymandered districts shall be thrown out and replaced such that (emphasis mine):<br />
<blockquote class="tr_bq">
any congressional districting plan shall consist of: congressional districts composed of <b>compact</b> and <b>contiguous</b> territory; as nearly <b>equal in population</b> as practicable; and which <b>do not divide</b> any county, city, incorporated town, borough, township, or ward, except where necessary to ensure equality of population. </blockquote>
I stared at this paragraph for a boggled minute because the English clauses aren't clearly laid out in a prioritized order. Rationalizing it combined with what I know of redistricting law, I think the priority has to work out to be:<br />
<br />
<ol>
<li>contiguous</li>
<li>equal population</li>
<li>whole towns</li>
<li>compact</li>
</ol>
If that is a <i>complete</i> statement of what the Pennsylvania courts want out of a district map, it's relatively simple. I clearly need to get hacking on the municipality-preserving version of my compact district solver.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com4tag:blogger.com,1999:blog-8483818569991829896.post-3253312663621103362017-11-27T22:49:00.000-05:002017-11-27T22:49:19.879-05:00Brown CS k-means Redistricting<a href="https://www.blogger.com/goog_148260894">K-Means redistricting at Brown U</a><br />
<a href="https://news.brown.edu/articles/2017/11/redistricting">https://news.brown.edu/articles/2017/11/redistricting</a><br />
<br />
I tried this 10 years ago and it's fast and simple but it isn't good enough.<br />
<br />
The solver in the article seems to completely ignore existing boundaries including the boundaries to which the Census has actually counted data called 'blocks' (sometimes a city block, sometimes an empty square mile of Montana). If they're assuming that population is fungible and uniformly distributed within a Census block I think that's invalid. My k-means solver drew those nice straight lines but then assigned whole blocks based on whether the center of the block was one side of the line or the other. All the districts thus had ragged edges.<br />
<br />
Because the k-means algorithm has very few data points to fiddle (district center, district weight) it can't find complex solutions. When I ran a k-means solver it couldn't find districts with close enough to equal population in a few places.<br />
<br />
I eventually went with a solver that considered one at a time each block on a border of two districts to see if a block would be better moved to the other district. That kind of detail and flexibility made maps that weren't as ideally simple, but still had good compactness, had much better equal-population constraint satisfaction, and should be much more workable for observing the same Census blocks that existing redistricting is done on.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com3tag:blogger.com,1999:blog-8483818569991829896.post-40932023136930232152017-10-06T08:42:00.000-04:002017-10-06T08:42:06.380-04:00Sotomayor on Gerrymandering's Absurdity"Could you tell me what the value is to democracy from political gerrymandering?<br />
How -- how does that help our system of government?"<br />
...<br />
"... it's okay to stack the decks so that for 10 years or an indefinite period of time one party, even though it gets a minority of votes, can't get a minor -- gets a minority of votes, can get the majority of seats?"<br />
-- Justice Sonia Sotomayor<br />
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<br /></div>
<div>
from oral arguments before the Supreme Court of the United States in the case of Gill v Whitford (on the matter of gerrymandering in Wisconsin)</div>
<div>
https://www.supremecourt.gov/oral_arguments/argument_transcripts/2017/16-1161_kjfm.pdf</div>
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<br /></div>
Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com2tag:blogger.com,1999:blog-8483818569991829896.post-56442480373853313152017-10-04T08:59:00.002-04:002017-10-04T08:59:33.990-04:00How the SCOTUS Wisconsin Gerrymander case could goA. Partisan gerrymander bad! Must gerrymander districts to ensure shoddy proportional representation.<br />
B. Partisan gerrymander bad! Map must provably have no bias.<br />
C. Meh. Whatever. Let whatever party do whatever they want.<br />
D. BS! Puny anti-gerrymandering arguments are so bad we don’t want any courts to listen to them in 2021 either.<br />
<br />
I feel like the plaintiffs want A. I feel like this is pretty unlikely. It would be a truly revolutionary decision that would effectively create new rules about how every state needs to redistrict. The Court is loathe to do this. Congress could pass a new 'Voting Rights Act' type law which could do this, if Congress could pass anything useful.<br />
<br />
Option B would be the court pulling a rabbit out of a hat. I'm not sure anyone is asking for this except me.<br />
<br />
I would mostly bet on C. No change, no big decision either way.<br />
<br />
I am afraid of D. The court could make a ruling such that they not only throw out the Wisconsin complaint but throw out the basis and statistical means of the Wisconsin complaint thus removing the basis for future court challenges. I know a lot of people who are betting on playing a good court challenge game in 2021 to battle the expected gerrymanders which come after the next Census. There would be a lot of searching for a new strategy between now and then if SCOTUS actively disqualifies the tests being tried in the Wisconsin case.<br />
<br />
---<br />
<br />
Things are in the news now, we can read snippets of the arguments in Court, but there won't be real news until the justices make their decision in the coming months.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com4tag:blogger.com,1999:blog-8483818569991829896.post-36504083357847595472017-08-09T14:39:00.001-04:002017-08-09T14:39:29.748-04:00Compute budgetI heard of a computational anti-gerrymandering project with a 6,000,000 cpu-hour budget on a university cluster supercomputer. I worked out that my main run in 2011 was a bit under 20,000 cpu-hours. My project at current prices with AWS spot instances or GCE interruptible instances that works out to $130-$150. That's a bit cheaper than what I paid for my home computer, and I could parallelize and do all the compute in a week instead of stringing it out over six months.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com1tag:blogger.com,1999:blog-8483818569991829896.post-31747883030076318072017-06-29T16:12:00.000-04:002017-06-29T16:12:11.303-04:00Black Votes MatterI have perhaps spent too much time on the math and the engineering of perfect ideal non-gerrymandered districts, and it is a good ideal, and it is not enough.<br />
<br />
The <a href="https://en.wikipedia.org/wiki/Voting_Rights_Act_of_1965">Voting Rights Act of 1965</a> decreed that there shall be a few majority-minority districts in states that had historically discriminated against African Americans by gerrymandering away their ability to get a majority in any congressional district. This of course introduces a different kind of deviation away from what purely 'impartial' districts might be. We might call what the VRA did 'gerrymandering for good' in that it constructed districts towards a specific end, the classic mode of gerrymandering, but for a purpose we call good. We could call it 'electoral reparations'. In an ideal world we would not need this and we would have districts that were compact or guided by enlightened social interest towards representing identifiable regions of people with common regional interest. In an ideal world ideological and identity representation would be handled by a <a href="https://en.wikipedia.org/wiki/Proportional_representation">Proportional Representation</a> system. But we do not live in an ideal world. Voter suppression in America, whether by under equipped precincts or by gerrymandering or by the poll tax of voter-id laws, primarily hurts the poor and non-white. I hope that someday we will build a more perfect union, but for now we still need those electoral reparations.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com1tag:blogger.com,1999:blog-8483818569991829896.post-67813932375810967702017-06-19T22:37:00.000-04:002017-06-19T22:37:20.533-04:00The SCOTUS Wisconsin Case<span style="font-family: inherit;"><span style="background-color: #fefefe; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;"><a href="https://www.washingtonpost.com/politics/courts_law/supreme-court-to-hear-potentially-landmark-case-on-partisan-gerrymandering/2017/06/19/d525237e-5435-11e7-b38e-35fd8e0c288f_story.html">SCOTUS will hear the Wisconsin case</a>. They've never overturned a </span><i style="-webkit-tap-highlight-color: transparent; background-color: #fefefe; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;">partisan</i><span style="background-color: #fefefe; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;"> gerrymander, only </span><i style="-webkit-tap-highlight-color: transparent; background-color: #fefefe; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;">racial</i><span style="background-color: #fefefe; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;"> gerrymanders. They could also still decline to rule on this case. By 5-4 they overturned the lower court's ruling that new districts needed to be enacted for this fall, so the gerrymander persists and justice will continue to be delayed and denied.</span><span style="font-family: inherit;"><br style="-webkit-tap-highlight-color: transparent; background-color: #fefefe; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;" /></span><span style="background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;">We could argue to SCOTUS that gerrymandering is </span><i style="-webkit-tap-highlight-color: transparent; background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;">bad</i><span style="background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;"> and it might not matter; they have to find it </span><i style="-webkit-tap-highlight-color: transparent; background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;">unconstitutional</i><span style="background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;"> and that's a trickier thing.</span></span><br />
<span style="background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;"><span style="font-family: inherit;"><br /></span></span>
<span style="font-family: inherit;"><span style="background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;">The way I understand the question it's about the 'equal protection' clause of the 14th amendment and whether 'equal protection' implies 'equal representation' and that implies that people need to have representatives of their own preferred party in State Legislature and Congress. If you register D party are you only properly treated by your government if there are D representatives in proportion to the number of D voters in your state? Traditionally the answer is No, you have a representative from your district and that's what you get whether you agree with them or not. Maybe the exception for racist gerrymanders confused the issue by enacting reparations for what was clearly a pattern of minority disempowerment. I think it's a tenuous line of reasoning and certainly not an 'originalist' interpretation of the Constitution.</span><br style="-webkit-tap-highlight-color: transparent; background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;" /><br style="-webkit-tap-highlight-color: transparent; background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;" /><span style="background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;">If they decide against Wisconsin it could be a really big deal requiring the redrawing of districts in a dozen states. I'm feeling a little cynical in betting the won't do that. If they do, it might come with a provision that nobody needs to change their districts this late and can just wait until 2021.</span><br style="-webkit-tap-highlight-color: transparent; background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;" /><br style="-webkit-tap-highlight-color: transparent; background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;" /><span style="background-color: white; color: rgba(0, 0, 0, 0.87); font-size: 14px; white-space: pre-wrap;">All that aside I of course do think that making our elected representatives more accurately mirror the voting populace is a good idea and making our legislative bodies more proportional is a good idea; I just think we'll need changes to laws and constitutions to make it happen.</span></span>Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com3tag:blogger.com,1999:blog-8483818569991829896.post-57467804835889822002017-02-24T15:43:00.000-05:002017-02-24T15:43:01.045-05:00Redistricting Summer School at Tufts U (Boston, MA)Tufts University is running a <a href="https://sites.tufts.edu/gerrymandr/">special one week program on redistricting and gerrymandering this summer</a>. There's a bunch of general interest material and three special training tracks in: how to be an expert witness in gerrymandering court battles, teaching about redistricting and gerrymandering at the high school and college level, and use of GIS software in redistricting.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com3tag:blogger.com,1999:blog-8483818569991829896.post-52349468639364384362017-02-23T22:40:00.000-05:002017-02-23T22:40:09.698-05:00Increased InterestEmails are up. I've been getting a lot of interest in my redistricting work in the last few months. People have been writing in to ask how they might start a ballot initiative in their state. A couple state legislators have even written in to ask for details on what I've worked out for there state and if I might do some customizations for them in the future.<br />
<br />
Sometimes people ask for an organization they can work with on practical reform efforts. In various local cases the <a href="http://lwv.org/issues/redistricting">League of Women Voters</a> has been key, and sometimes <a href="http://www.commoncause.org/issues/voting-and-elections/redistricting/">Common Cause</a> has been a good mover of note. The <a href="https://www.aclu.org/issues/voting-rights/gerrymandering">ACLU</a> seems to focus elsewhere, but does have some redistricting work.<br />
<br />
There's a lot of reform minded thought going around and I'm glad for it. Let's get these things nailed down by 2020 so we're ready to go when the Census data starts coming out in 2021.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com4tag:blogger.com,1999:blog-8483818569991829896.post-78820157823340860512017-02-06T19:08:00.001-05:002017-02-06T19:08:27.261-05:00Partisan Gerrymandering Supercomputing Statistical Analysis<a href="http://www.ncsa.illinois.edu/news/story/blue_waters_supercomputer_used_to_develop_a_standard_for_partisan_gerrymand">Gerrymandering analysis at UIUC</a> [1] uses a supercomputer cluster to generate millions of plausible districts and measures their goodness and partisan balance. Given this space of plausible district mappings, one can look at the current map and see if it is an outlier. They show one state, Maryland, and how its current map is at outlier on a couple metrics, and therefore probably an intentional partisan gerrymander. The motivation for this approach seems to be to create a tool for court challenges to gerrymandered maps. If a map is an outlier, highly unlikely by random chance, then it's probably due to malicious intent.<br />
<br />
I wish them luck and I hope they overturn some gerrymanders. I'll probably stick to my work of making one good map to compare to. If I can make one good map that's legally and practically viable, and measure its goodness and compare to other maps, then we should just let the best map win.<br />
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<span style="font-family: 'AdvPS3D3A15'; font-size: 8.000000pt;">[1] Election Law Journal, </span><span style="font-family: AdvPS3D3A15; font-size: 8pt;">ELECTION LAW JOURNAL
Volume 15, Number 4, 2016,</span><span style="font-family: AdvPS3D3A15; font-size: 8pt;"> DOI: 10.1089/elj.2016.0384 </span><span style="font-family: AdvPS3D3A15;"><span style="font-size: 10.6667px;">http://cho.pol.illinois.edu/wendy/papers/talismanic.pdf</span></span><br />
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Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com7tag:blogger.com,1999:blog-8483818569991829896.post-35166138155670724942016-12-02T14:16:00.000-05:002016-12-02T14:16:03.734-05:00Gerrymander Law GeekingHere's <a href="http://election.princeton.edu/2016/11/24/a-lower-court-win-on-partisan-gerrymandering/">a pretty good article about the state of gerrymandering law and court decisions as of November 2016</a>.<br />
<br />
One thing it says that in recent court decisions <i>shape is not enough</i>. Partisan demographics and racial demographics <b>are</b> enough to determine that a gerrymander has happened to the point that a court can throw it out. I think this implicitly declares that in order to do it right the first time, these features of demography would have to be accounted for in the initial district drawing after a Census. Party affiliation isn't part of the Census, but it's State data in the voter registration files.<br />
<br />
Designing districts towards demographic ends is at best <i>gerrymandering for good</i> or <i>shoddy proportional representation</i>.<br />
<br />
I still think that if we want <b>proportional representation</b> then we should actually do that and not fake it with badly drawn districts. I think we need an answer to the question: <b>what is a district for?</b> I think it is for representing a locality or a region. But, in practice, maybe it's for electing a representative. And we want our representatives to follow our population; and that means some kind of proportionality. So, if locality or region doesn't matter, and we have to have districts, then draw the district however is needed to meet the demographic goals. And now my logic is eating its own tail and I'm back to the conclusion I started with, we want proportional representation, and we should do it right.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com4tag:blogger.com,1999:blog-8483818569991829896.post-24540679156243292112016-11-27T21:52:00.002-05:002016-11-27T21:52:43.813-05:00Ranked Voting ToolsAside from redistricting, my other favorite issue around election reform is getting beyond 'pick one' ballots to rankings or ratings voting. It's what elections should be. We can start right away using it at every level to make better decisions. Picking an office outing? Officer of your club? Here are some tools:<br />
<br />
<a href="https://bolson.org/cgi-bin/election_maker">https://bolson.org/cgi-bin/election_maker</a><br />
Paper ballots. This makes ranked ballots you can print and fill out on paper; also a tabulation sheet for counting with Condorcet’s method. (Instructional video is planned.)<br />
<br />
<a href="http://betterpolls.com/do/v8uIlar1ufph">http://betterpolls.com/do/v8uIlar1ufph</a><br />
Online votes. I linked to an silly example voting between four flavors of ice cream. But make any poll you like there. Requires fb or google log in to create a poll or vote. Doesn’t spam anyone, just make a link and send the link to people you want to vote.Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com6tag:blogger.com,1999:blog-8483818569991829896.post-35277716289862251732016-11-11T10:02:00.001-05:002016-11-11T15:54:46.661-05:00Towards Redistricting Reform in OregonI'm working with some people in Oregon to start working towards a ballot initiative to change the state constitution to use fully automated impartial redistricting. If you know anyone active in Oregon politics, please share this with them.
<a href="https://drive.google.com/open?id=0Bxe5HJVKoarbY2hNVXNjQ1FER2R5TnVfRHlKNmVJMmowbDdz">Proposed ballot initiative for redistricting reform in Oregon, as of 2016-11-11</a>Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com1tag:blogger.com,1999:blog-8483818569991829896.post-58581607558081912372016-11-10T21:16:00.002-05:002016-11-11T14:45:39.762-05:00Fixed AlaskaFor years my software broke when trying to deal with Alaska because its longitudes straddle the -180/180 split. My simplistic cartesian software couldn't handle this. Also it was probably horribly warped by using a naive mercator style projection. But no more!
Now I use the proj4 geographic projection library to optionally warp a state to an azimuthal equal area projection centered over the state so that there is relatively little distortion anywhere within it. This also normalizes the coordinates to all fit in a simple x,y bounding box.
So, I now have 20 districts for the Alaska state Senate and 40 districts for the state House and they look pretty good:
<a href="http://bdistricting.com/2010/AK_Senate/">http://bdistricting.com/2010/AK_Senate/</a>
<a href="http://bdistricting.com/2010/AK_House/">http://bdistricting.com/2010/AK_House/</a>Brian Olsonhttp://www.blogger.com/profile/06258128480111746553noreply@blogger.com1