An impossibility theorem for gerrymandering
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An impossibility theorem for gerrymandering
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Re: An impossibility theorem for gerrymandering
#2Totally. This is why in the more recent gerrymandering thread I was making such a big deal about the efficiency gap rather than geometry for detecting this stuff. Geometry is just a flawed heuristic for a multitude of reasons.
That's why the efficiency gap is so exciting as a measure.
Re: An impossibility theorem for gerrymandering
#3I'm confused about the example.
First of all, it seems highly unlikely such a distribution of red and blue votes would occur. But more importantly, blue is a majority of every 3x3 square - why shouldn't it win every district?
Re: An impossibility theorem for gerrymandering
#4So the question is if "Minimizing Efficiency Gap" is what we should be aiming for.
Its a solid proposal, but I guess its up to the courts to decide if "Efficiency Gap" is a good metric. I guess I'll be interested in hearing the arguments as they come up.
Re: An impossibility theorem for gerrymandering
#5I'm confused about the example. First of all, it seems highly unlikely such a distribution of red and blue votes would occur. But more importantly, blue is a majority of every 3x3 square - why shouldn't it win every district?
> why shouldn't it win every district?
Because we are supposed to have a representative government. If there's 55% Blue voters and 45% Red Voters, you're supposed to ideally have 55% Blue representatives and 45% Red representatives.
The example is a counterexample of this concept. Instead of 55% Blue / 45% Red split, the map as a whole becomes 100% blue. This is almost the very definition of "Tyranny of the Majority".
Re: An impossibility theorem for gerrymandering
#6I'm confused about the example. First of all, it seems highly unlikely such a distribution of red and blue votes would occur. But more importantly, blue is a majority of every 3x3 square - why shouldn't it win every district?
> why shouldn't it win every district? Because we are supposed to have a representative government. If there's 55% Blue voters and 45% Red Voters, you're supposed to ideally have 55% Blue representatives and 45% Red representatives. The example is a counterexample of this concept. Instead of 55% Blue / 45% Red split, the map as a whole becomes 100% blue. This is almost the very definition of "Tyranny of the Majority"…
If votes are 80-20 then it's not necessarily possible or reasonable to draw 80 vs 20 winning districts.
Re: An impossibility theorem for gerrymandering
#7I suspect Gerrymandering isn't uniquely a US problem. I do a lot of UK Census spatial analysis and the district centroids that are used create problems. In the article the 'ear muffs' shape would create a centroid for the voting district outside of the district, given that the shape of the district was designed to give a certain ethnic group a voice, whereas the process for creating districts in the UK are done usually on the idea of 'belonging' to a town/village/area and are decided and audited at a national 'neutral' level.
The data scientist in me wants centroids around circles with fuzzy edges. If we could all agree that fuzzy circles is the way forward we could solve gerrymandering over night.
The reality is though, that I create these amazing pieces of analysis then have to explain away why that district is odd, y'know, cos the shape is just weird.
Locally they are redoing the district boundaries which is giving me an opportunity to submit my own district shapes that work better with Census data :D
Re: An impossibility theorem for gerrymandering
#8I'm confused about the example. First of all, it seems highly unlikely such a distribution of red and blue votes would occur. But more importantly, blue is a majority of every 3x3 square - why shouldn't it win every district?
> blue is a majority of every 3x3 square
Blue is indeed a slight majority of every "3x lattice"-aligned square. But if you take the top left square and shift one down and one right, you'll see that in fact red wins that 3x3 square decisively: 8 to 1.
> why shouldn't it win every district?
Maybe you think it should, but whoever drew the districts would run afoul of the newish gerrymandering measure the Supreme Court is considering.
Re: An impossibility theorem for gerrymandering
#9So the question is if "Minimizing Efficiency Gap" is what we should be aiming for. Its a solid proposal, but I guess its up to the courts to decide if "Efficiency Gap" is a good metric. I guess I'll be interested in hearing the arguments as they come up.
It seems to me that a system with zero efficiency gap would be equivalent to one big election with proportional representation. If that's what people really want, why talk about voting districts at all?
Re: An impossibility theorem for gerrymandering
#10So the question is if "Minimizing Efficiency Gap" is what we should be aiming for. Its a solid proposal, but I guess its up to the courts to decide if "Efficiency Gap" is a good metric. I guess I'll be interested in hearing the arguments as they come up.
I'm not sure I like the name "Efficiency Gap" but the metric of "require the overall district results be within a certain range of the popular results" seems pretty straightforward to me.
I've always thought they should just reverse the order of operations. Instead of having people draw the districts, then machines evaluate them, they should have machines draw a bunch of potential "low efficiency gap" districts, then let people pick the best ones.