7 ms·

Show HN: Antimander – Optimize Congressional Districts with Genetic Algorithms

68 points by joelS 6y ago

rpedela 6y ago
On Android and Chrome, I can't read the page. The graphic takes up half the screen and the text underneath is barely visible.
- jimhefferon 6y ago
  For me also.
- pdxandi 6y ago
  I had to scroll all the way to the bottom to see if anyone could even read the site on mobile.
c54 6y ago
This is really well done! Do you have analysis of what this would do nationwide or across multiple states? Optimizing for competitiveness is a metric I hadn’t considered but seems particularly valuable especially towards increasing voter turnout.
- jojobas 6y ago
  How is it valuable? Having a "red" or "blue" district means the congressman is somebody most people can get behind, "our guy in the parliament". Being around 50% gives you a compromise that nobody trusts and nobody feels the stake in their country.
gillesjacobs 6y ago
Gerrymandering is a danger to democracy and it is great that researchers shine light on the different trade-offs of districting criteria. This website seems like a great demonstration of the fairness and competitiveness trade-offs.
- usrusr 6y ago
  I'd argue that every voting system that has gerrymandering as a possibly error mode is inherently dangerous. No amount of antimandering could ever be more than a temporal band-aid. There are many examples that successfully combine local representation with proportional outcome.
jojobas 6y ago
>Some interesting patterns emerge, such as how with you can have compact and republican-biased but not compact and democrat-biased maps for some numbers of cities. This is a direct result of one party being forced into a small geographic area (cities). That's quite an interesting finding. I always understood that gerrymandeting is bad because the artificially winning parties get congressmen that are not representative of their districts. This guy uses "competitiveness" as a property worth optimizing for, achieving exactly that.
- specialist 6y ago
  I've long advocated maximal competitiveness. Mostly to motivate voter participation. I love how antimander illuminates the tradeoffs. Along the lines of "preserving community", preserving continuity can also be a factor. On the presumption that voters don't want to have their congressional district designation changed every 10 years. For example. I know this is a consideration during redistricting. -- Antimander is real progress. The cites are terrific. I'm delighted that I even learned some new things, like the Seats-Votes Curve. I've spoken with the Dave Bradlee many times over the last 15 years. He created a redistricting app that got some national media attention last cycle. https://en.wikipedia.org/wiki/Dave%27s_Redistricting https://en.wikipedia.org/wiki/Dave%27s_Redistricting Some of those talks were pretty bleak. I'm so glad so many more people have engaged with this issue.
steve_gh 6y ago
Interesting. GA's have some interesting use cases. We used a GA to optimize assignment of work crews to areas as part of a scheduling optimization, and achieved significant benefits Steve
- kwaldman 6y ago
  Seen similar benefits - many years ago applied GA's to schedule technicians to fix computers (based on location, part availability, skill set, etc) and also for manufacturing production lines (labor rules, parts, color changeovers, demand, margin)
FiReaNG3L 6y ago
Interesting to note that the very same tool can be used to optimize the 'worst' maps as well.
charleskinbote 6y ago
Along the same thread, genetic algorithms have been used to evaluate fair land allocation in Brazil [1], which have also historically been done by hand. I agree with another user that pointed out the very same tools can be used to gerrymander even more effectively than those districts are currently, perhaps in less obvious ways, without the oddly shaped borders that stretch wildy from place to place. It would be important not to have this occur behind closed doors but left open to scrutiny where the fitness function and biases are in full view. [1] https://www.lume.ufrgs.br/bitstream/handle/10183/174950/001065460.pdf?sequence=1 https://www.lume.ufrgs.br/bitstream/handle/10183/174950/0010...
splitrocket 6y ago
"I cut, you choose" is really the only politically viable alternative to the current state of affairs. https://slate.com/news-and-politics/2018/02/how-the-i-cut-you-choose-method-of-redistricting-could-fix-a-broken-system.html https://slate.com/news-and-politics/2018/02/how-the-i-cut-yo...
- chrisbrandow 6y ago
  It would require a more fundamental recognition of political parties than the constitution provides. Gerrymandering is not a technological problem.
  - fastball 6y ago
    Why can't you just split elected representatives into two groups, regardless of stated political affiliation? One group then cuts, the other chooses.
    - specialist 6y ago
      Defections. Electeds will happily maximize their own personal power at someone else's expense. There are many examples of getting opposition support for inequity in exchange for safe seats. People outside of (partisan) politics don't often get to see that the party orgs and the politicians are usually in conflict. More so on the left than on the right.
      - splitrocket 6y ago
        Interestingly enough, this works even for defectors. They still have to participate in a turn-based game against a competitor. There is a whole field of study around efficient "cake cutting" algorithms, many of which contemplate and account for defectors. https://en.wikipedia.org/wiki/Fair_cake-cutting https://en.wikipedia.org/wiki/Fair_cake-cutting
  - splitrocket 6y ago
    Unfortunately, given Duverger's law [0], first past the post electoral systems eventually resolve into two party systems. Essentially, in a first past the post system, voting for any other candidate other than the one both most likely to win AND whose politics most closely aligns with your own is effectively a vote for the major party candidate who least aligns with your politics. [0] https://en.wikipedia.org/wiki/Duverger%27s_law https://en.wikipedia.org/wiki/Duverger%27s_law edit for link.
xorfish 6y ago
How hard would it be to change the congressional election system to proportional voting by party? In California you would vote for 53 representatives, each representative would be part of a party. First the seats are divided among all parties based on some system. Then within each party the seats are given to the representatives that have the most votes within the party. This would introduce new parties to the system, no party would be able to govern alone.
- cbuq 6y ago
  Would this require me to make 53 different votes? This sounds a like pretty complicated situation to expect educated votes for all 53 votes.
  - rsynnott 6y ago
    In practice, in mostly countries that use STV PR, you have smaller electoral districts, for this reason. For instance, in Ireland, electoral districts elect 3-5 TDs depending on population. This is big enough to make gerrymandering difficult and not very effective, but small enough to avoid the situation where someone has to cast 53 different votes. And 53 would be the low end here, really. That would assume you only want to vote for one candidate per seat, which is not typically the way it works out. I'm in a four seat constituency and voted about ten preferences in the last election, say. In practice, in STV PR it is generally optimal to vote for almost everyone on the ballot; you give low preferences to people you don't care about to avoid people you actively don't want getting in (it's commonly claimed that you should optimally give a preference to everyone, even those you actively don't want, but this is incorrect).
  - xorfish 6y ago
    Usually each party would provide a list with their preferred representatives that can be modified. Where I life, you can give up to 2 votes per representative. You don't need to choose 54 different politicians because "empty" votes will still count for the party. Most people will just use the list of their party and maybe remove some that they don't like or vote double for someone they like.
IgorPartola 6y ago
As Congressional elections become more and more a national affair, why do we still have districts? Say a state gets 24 reps. Give me a ballot with all the candidates and let me mark the 24 I want. Yes the ballot will be more complicated, but this way we entirely avoid districting and the process is entirely fair (well until you consider states not being fairly drawn, but that’s one level up).
- antishatter 6y ago
  That of course defeats the purpose of smaller districts getting a voice and not being crushed by larger districts.
  - IgorPartola 6y ago
    Yes. That’s a feature, not a bug. 10m people in a city should get 10x the say than 1m people in the surrounding rural land. Why would you ever want it to be different other than trying to skew elections towards giving rural residents disproportionate amounts of voting power?
- coldcode 6y ago
  Likely it means that big cities would get all the reps and the rest of the state gets nothing.
  - dhosek 6y ago
    A better route would be proportional representation. You vote for a party-ranked list of candidates, and the top n% of the list gets into office based on the fraction of the vote the party received. Unlike single-member plurality voting, this makes third parties viable.
  - jgeada 6y ago
    As that is where most of the people live, why is it wrong? Why does largely unpopulated land get a vote?
nicolaskruchten 6y ago
I've always like this article's thoughtful approach to what we should value when districting: https://www.politico.com/magazine/story/2015/06/could-gerrymandering-be-good-for-democracy-119581 https://www.politico.com/magazine/story/2015/06/could-gerrym...
bargle0 6y ago
Now do Maryland.

68 points by joelS 6y ago

On Android and Chrome, I can't read the page. The graphic takes up half the screen and the text underneath is barely visible.

jimhefferon 6y ago
For me also.
pdxandi 6y ago
I had to scroll all the way to the bottom to see if anyone could even read the site on mobile.

c54 6y ago

This is really well done! Do you have analysis of what this would do nationwide or across multiple states? Optimizing for competitiveness is a metric I hadn’t considered but seems particularly valuable especially towards increasing voter turnout.

jojobas 6y ago
How is it valuable? Having a "red" or "blue" district means the congressman is somebody most people can get behind, "our guy in the parliament". Being around 50% gives you a compromise that nobody trusts and nobody feels the stake in their country.

gillesjacobs 6y ago

Gerrymandering is a danger to democracy and it is great that researchers shine light on the different trade-offs of districting criteria. This website seems like a great demonstration of the fairness and competitiveness trade-offs.

usrusr 6y ago
I'd argue that every voting system that has gerrymandering as a possibly error mode is inherently dangerous. No amount of antimandering could ever be more than a temporal band-aid. There are many examples that successfully combine local representation with proportional outcome.

jojobas 6y ago

>Some interesting patterns emerge, such as how with you can have compact and republican-biased but not compact and democrat-biased maps for some numbers of cities. This is a direct result of one party being forced into a small geographic area (cities). That's quite an interesting finding. I always understood that gerrymandeting is bad because the artificially winning parties get congressmen that are not representative of their districts. This guy uses "competitiveness" as a property worth optimizing for, achieving exactly that.

specialist 6y ago
I've long advocated maximal competitiveness. Mostly to motivate voter participation. I love how antimander illuminates the tradeoffs. Along the lines of "preserving community", preserving continuity can also be a factor. On the presumption that voters don't want to have their congressional district designation changed every 10 years. For example. I know this is a consideration during redistricting. -- Antimander is real progress. The cites are terrific. I'm delighted that I even learned some new things, like the Seats-Votes Curve. I've spoken with the Dave Bradlee many times over the last 15 years. He created a redistricting app that got some national media attention last cycle. https://en.wikipedia.org/wiki/Dave%27s_Redistricting https://en.wikipedia.org/wiki/Dave%27s_Redistricting Some of those talks were pretty bleak. I'm so glad so many more people have engaged with this issue.

steve_gh 6y ago

Interesting. GA's have some interesting use cases. We used a GA to optimize assignment of work crews to areas as part of a scheduling optimization, and achieved significant benefits Steve

kwaldman 6y ago
Seen similar benefits - many years ago applied GA's to schedule technicians to fix computers (based on location, part availability, skill set, etc) and also for manufacturing production lines (labor rules, parts, color changeovers, demand, margin)

FiReaNG3L 6y ago

Interesting to note that the very same tool can be used to optimize the 'worst' maps as well.

charleskinbote 6y ago

Along the same thread, genetic algorithms have been used to evaluate fair land allocation in Brazil [1], which have also historically been done by hand. I agree with another user that pointed out the very same tools can be used to gerrymander even more effectively than those districts are currently, perhaps in less obvious ways, without the oddly shaped borders that stretch wildy from place to place. It would be important not to have this occur behind closed doors but left open to scrutiny where the fitness function and biases are in full view. [1] https://www.lume.ufrgs.br/bitstream/handle/10183/174950/001065460.pdf?sequence=1 https://www.lume.ufrgs.br/bitstream/handle/10183/174950/0010...

splitrocket 6y ago

"I cut, you choose" is really the only politically viable alternative to the current state of affairs. https://slate.com/news-and-politics/2018/02/how-the-i-cut-you-choose-method-of-redistricting-could-fix-a-broken-system.html https://slate.com/news-and-politics/2018/02/how-the-i-cut-yo...

chrisbrandow 6y ago
It would require a more fundamental recognition of political parties than the constitution provides. Gerrymandering is not a technological problem.
- fastball 6y ago
  Why can't you just split elected representatives into two groups, regardless of stated political affiliation? One group then cuts, the other chooses.
  - specialist 6y ago
    Defections. Electeds will happily maximize their own personal power at someone else's expense. There are many examples of getting opposition support for inequity in exchange for safe seats. People outside of (partisan) politics don't often get to see that the party orgs and the politicians are usually in conflict. More so on the left than on the right.
    - splitrocket 6y ago
      Interestingly enough, this works even for defectors. They still have to participate in a turn-based game against a competitor. There is a whole field of study around efficient "cake cutting" algorithms, many of which contemplate and account for defectors. https://en.wikipedia.org/wiki/Fair_cake-cutting https://en.wikipedia.org/wiki/Fair_cake-cutting
- splitrocket 6y ago
  Unfortunately, given Duverger's law [0], first past the post electoral systems eventually resolve into two party systems. Essentially, in a first past the post system, voting for any other candidate other than the one both most likely to win AND whose politics most closely aligns with your own is effectively a vote for the major party candidate who least aligns with your politics. [0] https://en.wikipedia.org/wiki/Duverger%27s_law https://en.wikipedia.org/wiki/Duverger%27s_law edit for link.

xorfish 6y ago

How hard would it be to change the congressional election system to proportional voting by party? In California you would vote for 53 representatives, each representative would be part of a party. First the seats are divided among all parties based on some system. Then within each party the seats are given to the representatives that have the most votes within the party. This would introduce new parties to the system, no party would be able to govern alone.

cbuq 6y ago
Would this require me to make 53 different votes? This sounds a like pretty complicated situation to expect educated votes for all 53 votes.
- rsynnott 6y ago
  In practice, in mostly countries that use STV PR, you have smaller electoral districts, for this reason. For instance, in Ireland, electoral districts elect 3-5 TDs depending on population. This is big enough to make gerrymandering difficult and not very effective, but small enough to avoid the situation where someone has to cast 53 different votes. And 53 would be the low end here, really. That would assume you only want to vote for one candidate per seat, which is not typically the way it works out. I'm in a four seat constituency and voted about ten preferences in the last election, say. In practice, in STV PR it is generally optimal to vote for almost everyone on the ballot; you give low preferences to people you don't care about to avoid people you actively don't want getting in (it's commonly claimed that you should optimally give a preference to everyone, even those you actively don't want, but this is incorrect).
- xorfish 6y ago
  Usually each party would provide a list with their preferred representatives that can be modified. Where I life, you can give up to 2 votes per representative. You don't need to choose 54 different politicians because "empty" votes will still count for the party. Most people will just use the list of their party and maybe remove some that they don't like or vote double for someone they like.

IgorPartola 6y ago

As Congressional elections become more and more a national affair, why do we still have districts? Say a state gets 24 reps. Give me a ballot with all the candidates and let me mark the 24 I want. Yes the ballot will be more complicated, but this way we entirely avoid districting and the process is entirely fair (well until you consider states not being fairly drawn, but that’s one level up).

antishatter 6y ago
That of course defeats the purpose of smaller districts getting a voice and not being crushed by larger districts.
- IgorPartola 6y ago
  Yes. That’s a feature, not a bug. 10m people in a city should get 10x the say than 1m people in the surrounding rural land. Why would you ever want it to be different other than trying to skew elections towards giving rural residents disproportionate amounts of voting power?
coldcode 6y ago
Likely it means that big cities would get all the reps and the rest of the state gets nothing.
- dhosek 6y ago
  A better route would be proportional representation. You vote for a party-ranked list of candidates, and the top n% of the list gets into office based on the fraction of the vote the party received. Unlike single-member plurality voting, this makes third parties viable.
- jgeada 6y ago
  As that is where most of the people live, why is it wrong? Why does largely unpopulated land get a vote?

nicolaskruchten 6y ago

I've always like this article's thoughtful approach to what we should value when districting: https://www.politico.com/magazine/story/2015/06/could-gerrymandering-be-good-for-democracy-119581 https://www.politico.com/magazine/story/2015/06/could-gerrym...

bargle0 6y ago

Now do Maryland.