How to Solve Gerrymandering

Decades ago, my brother posited to me a the following scenario: When 2 children are cutting up a slice of cake to share, you should have one cut the cake in two and the other pick which slice they want.  This way, the cutter is incentivized to try to cut the pieces as equally as possible.  If they aren't equal, the picker will pick the bigger slice and the cutter will miss out.

My brother's question was this: Could a system for dividing a state into districts be similarly worked out?

Nope.  The cake is like a fungible good -- north side of the cake is made of the same stuff as the south side, same with east-west.  "But what if there's a cherry on it, and the cherry is precious?"  that's only if both children want the cherry equally, and if you can equate the cherry with a volume of cake.

Voting is different because there's parts of the "cake" that is unwanted by one of the children; voters who vote against you or abstain aren't of equivalent worth to people who would vote for you. If you're proficient in gerrymandering, you can cut the cake so that both parts are toxic enough to the other kid that they can't play no matter which piece they chose to eat. 

The key element here is the first-past-the-post voting system we have.  You got a cake that's 67% strawberry and 33% chocolate.  That's mostly strawberry, right?  Cut the cake into five pieces, two are entirely strawberry (20%, 20%), the other are mostly chocolate (11%c 9%s).  Now you've got 2 strawberry pieces and 3 chocolate pieces... for a chocolate majority.  Doesn't matter if the strawberry-loving kid "chooses" after the "cake" is cut.  This is why gerrymandering sucks.  Another reason for gerrymandering sucking is the rules for making the cut.  You're right that it fucking sucks the chocolate-loving kid gets to cut the next cake to make sure it mostly tastes like chocolate; the alternative, which we've already seen and may see again, is two kids wrestling over the knife and the cake growing mold while they fight (which is a weird way to say "civil war" and "military coup.")

aaand after I said "I cut you choose" won't work, here comes three dudes from Cambridge that came up with a way to make it work.

Redistricting reformers have proposed many solutions to the problem of partisan gerrymandering, but they all require either bipartisan consensus or the agreement of both parties on the legitimacy of a neutral third party to resolve disputes. In this paper, we propose a new method for drawing district maps, the Define–Combine Procedure, that substantially reduces partisan gerrymandering without requiring a neutral third party or bipartisan agreement. One party defines a map of $2N$ equal-population contiguous districts. Then the second party combines pairs of contiguous districts to create the final map of N districts. Using real-world geographic and electoral data, we employ simulations and map-drawing algorithms to show that this procedure dramatically reduces the advantage conferred to the party controlling the redistricting process and leads to less-biased maps without requiring cooperation or non-partisan actors.

https://www.cambridge.org/core/journals/political-analysis/article/partisan-solution-to-partisan-gerrymandering-the-definecombine-procedure/B0792DD0A49332944F2AF5FF6828E275

aaand after I said "I cut you choose" won't work, here comes three dudes from Cambridge that came up with a way to make it work.

Redistricting reformers have proposed many solutions to the problem of partisan gerrymandering, but they all require either bipartisan consensus or the agreement of both parties on the legitimacy of a neutral third party to resolve disputes. In this paper, we propose a new method for drawing district maps, the Define–Combine Procedure, that substantially reduces partisan gerrymandering without requiring a neutral third party or bipartisan agreement. One party defines a map of $2N$ equal-population contiguous districts. Then the second party combines pairs of contiguous districts to create the final map of N districts. Using real-world geographic and electoral data, we employ simulations and map-drawing algorithms to show that this procedure dramatically reduces the advantage conferred to the party controlling the redistricting process and leads to less-biased maps without requiring cooperation or non-partisan actors.

https://www.cambridge.org/core/journals/political-analysis/article/partisan-solution-to-partisan-gerrymandering-the-definecombine-procedure/B0792DD0A49332944F2AF5FF6828E275

Very interesting, so the first party creates a bunch of half-districts and the second party combines the halves into the final districts that will be used?