Government

Redistricting Game results, part 1: The fun part

by David Alpert   •   April 18, 2011 11:01 am

3,981 maps solving DC's redistricting puzzle were created using our Redistricting Game. What did people choose, and what conclusions can we draw? How should the DC Council redraw the ward boundaries?

The Redistricting Game wasn't just a game, and a lot of people made very serious maps trying to solve the redistricting problem in a realistic way. We'll take a close look at those maps this week.

Other people did inject some more whimsy into their maps, like these amusing maps from Zmapper where wards are stripes. In one, 7 wards cross the river. In the other, all touch the Potomac and DC's northeast border.

What about giving each Councilmember a piece of downtown? That would encourage everyone to care about that area, and give every ward a variety of densities from the greatest to the least. It would be easy to make sure every ward had a fair share of Capital Bikeshare stations or streetcar lines in such a system.

A few users wish Tommy Wells represented downtown. The map on the left changes this with minimal other modifications; the one on the right also tries for close to equal population.

On the left map below, the entire Red Line from Friendship Heights to New York Avenue is all in Ward 3. On the right, Ward 8 gets DC's north-south axis along South Capitol and North Capitol Streets almost all the way from one end to the other, while Ward 4 gets all of Georgia Avenue, Ward 1 all of 16th Street, and Ward 3 all of Connecticut Avenue.

Most of the maps don't take extreme measures just to create entertaining visual patterns. Most people tried to solve the redistricting problem while also keeping wards compact and generally in their current forms.

218 maps made the fewest number of changes, 3. There are a number of ways to do this. Here were the 4 most popular, zoomed in around the areas where the changes are:

On the flip side, here are the maps with the greatest number of changed areas:

The map below at left is closest to perfect equality in ward population, given the constraints of the tool which required moving whole census tracts as one. Naturally, if you can break up the tracts, there are infinite ways to make the wards come out as equal as possible. The right map is the least equal, with the highest standard deviation among ward sizes.

Wards 7 and 8 have to get larger, while 2 has to get smaller. That almost always requires changing something about 6 or 5 as well. There is one exception, if Ward 8 takes over part of the Mall and then one of the two tracts of Foggy Bottom (but not both, which would move too many people).

Who made the maps? The first step of the game asked people which of the areas they lived in. Based on that, we know their ward, assuming they were being honest and knew how to locate their homes on a map.

The first number, Started, is the number of times someone in that ward started the game. Completed is the number of times they finished a valid map. And the third number makes my best guess as to which ones are the same person, using the IP address and their choice of home area, and combines those likely duplicates into one.

I'm sure some people will suggest that the higher rates of maps being generated in some wards means that we should ignore all the results and instead just go with the recommendations of small committees selected by ward councilmembers, but a better solution is to be sure to look at the results for residents of each ward individually to see if there are differences. As I go through the analysis, I'll do just that.

In upcoming parts, we'll start looking at the serious topics to try to generate real, not-a-game policy recommendations.

David Alpert is the Founder and Editor-in-Chief of Greater Greater Washington and Greater Greater Education. He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He loves the area which is, in many ways, greater than those others, and wants to see it become even greater.