Countering gerrymandering in Pennsylvania with numerical models

Wired highlights a few academics who argued against gerrymandered political districts in Pennsylvania with models showing the low probability that the map is nonpartisan:

Then, Pegden analyzed the partisan slant of each new map compared to the original, using a well-known metric called the median versus mean test. In this case, Pegden compared the Republican vote share in each of Pennsylvania’s 18 districts. For each map, he calculated the difference between the median vote share across all the districts and the mean vote share across all of the districts. The bigger the difference, the more of an advantage the Republicans had in that map.

After conducting his trillion simulations, Pegden found that the 2011 Pennsylvania map exhibited more partisan bias than 99.999999 percent of maps he tested. In other words, making even the tiniest changes in almost any direction to the existing map chiseled away at the Republican advantage…

Like Pegden, Chen uses computer programs to simulate alternative maps. But instead of starting with the original map and making small changes, Chen’s program develops entirely new maps, based on a series of geographic constraints. The maps should be compact in shape, preserve county and municipal boundaries, and have equal populations. They’re drawn, in other words, in some magical world where partisanship doesn’t exist. The only goal, says Chen, is that these maps be “geographically normal.”

Chen generated 500 such maps for Pennsylvania, and analyzed each of them based on how many Republican seats they would yield. He also looked at how many counties and municipalities were split across districts, a practice the Pennsylvania constitution forbids “unless absolutely necessary.” Keeping counties and municipalities together, the thinking goes, keeps communities together. He compared those figures to the disputed map, and presented the results to the court…

Most of the maps gave Republicans nine seats. Just two percent gave them 10 seats. None even came close to the disputed map, which gives Republicans a whopping 13 seats.

It takes a lot of work to develop these models and they are based on particular assumptions as well as methods for calculations. Still, could a political side present a reasonable statistical counterargument?

Given both the innumeracy of the American population and some resistance to experts, I wonder how the public would view such models. On one hand, gerrymandering can be countered by simple arguments: the shapes drawn on the map are pretty strange and can’t truly represent any meaningful community. On the other hand, the models reinforce how unlikely these particular maps are. It isn’t just that the shapes are unusual; they are highly unlikely given various inputs that go into creating meaningful districts. Perhaps any of these argument are meaningless if your side is winning through the maps.

The difficulties of merging or dissolving local governments in Pennsylvania

Pennsylvania has the third-most local governments but there is difficulty in trying to merge or dissolve these bodies:

Lawmakers are considering a bill that would allow dissolution and limit municipalities’ stay in the state’s distressed program. Thirteen cities have been stuck with that designation for at least a decade, and fragmentation at the local level makes it harder to turn them around, said Matt Fabian, managing director at Concord, Mass.-based research firm Municipal Market Advisors…Some localities have shrunk so much they may be unable to operate, according to Ross. The communities are stagnating as Pennsylvania’s economy is falling behind, with job and population growth trailing most states, said Standard & Poor’s…

In Pennsylvania, every square inch of land must be incorporated, preventing dissolution. Municipalities in Connecticut, Delaware, Hawaii, Massachusetts, New Hampshire, New Jersey, North Carolina, Rhode Island and Vermont also restrict dissolution, said Michelle Wilde Anderson, who studies distressed communities as an assistant professor at University of California Berkeley School of Law…

The path of merger or consolidation is often unavailable because municipalities are reluctant to take on neighbors, which may be distressed.

This sounds like a two-step process:

1. Providing the legal means for dissolving local governments. Residents may not think about it much but a group of local residents can’t simply declare themselves an incorporated community or start collecting local taxes – this process has regulations and procedures.

2. But, even if such moves were legal, the article hints at another difficult issue: getting communities or governments to agree to merge with others. Americans are generally unwilling to give up local control, even in difficult financial times, or to take on the problems of nearby local entities that might threaten their quality of life. As an example, see the shift in the late 1800s as suburbs stopped desiring annexation from big cities.

Given the financial difficulties a lot of local governments face, I suspect stories about this will be more common in the coming years. Yet, consolidation or dissolving is not a quick process and generally requires consent from all parties involved.