Open source tool to evaluate redistricting proposals and stop gerrymandering

Dave sez,

The redistricting process is one of the most important -- yet least understood -- aspects of the US political system. It's full of smoke-filled back room dealmaking by political insiders with little public input. The result? Districts are often drawn by the policial parties themselves -- usually the majority party -- AKA gerrymandering. Because of this, district lines are altered by lawyers and politicians in ways that don't accurately reflect the citizens. It's a rigged process and the public has the power to get involved and keep government in check, but we need to first learn more about how it works.

The Public Mapping Project is an open-sourced software tool created to help the public better understand the redistricting process. It also enables users to make their own congressional maps which can be submitted to local government. Users as young as 10 have been drawing maps that are widely recognized to be better than proposals from the state. The tool was designed by Michael McDonald of George Mason University and Micah Altman of the Institute for Quantitative Social Science at, Harvard.

Colleges and universities throughout the country are now using this software to launch student mapping competitions. For example, next month Fordham University will host a New York state redistricting competition where teams of students throughout the state will design their own congressional and state legislative districts. These maps will then be judged by a panel of experts, the winning ones sent to Albany for consideration.

Public Mapping Project (Thanks, Dave!)


  1. The more I see government interfering with the internet in general, the more I think some politicians are afraid of losing the power to be opaque over government information and practices like gerrymandering.

    1. Have you ever met a politician? Great people skills, but not smart! In the past it took enough time to muckrake that most people didn’t do it, but the internet is creating people who are both interested to be involved, and big readers. We still haven’t yet seen a generational shift in US politics with respect to the internet.

      1. We still haven’t yet seen a generational shift in US politics with respect to the internet.

        The closest thing we’ve gotten is Obama and Ron Paul.  It’s off to a rough start but humanity will keep improving.

        OWS is the next step we’ve needed that simply wasn’t possible until the information age reached this level of maturity.  It’s a bunch of stumbling baby steps, but it’s happening, thank God.

  2. wow, this is a truly great idea for an app.  I hope it catches on everywhere – want one for Canada.  Can think of all kinds of things to do with apps along these lines….

  3. The best suggestion I’ve ever heard for redistricting calls for all districts to have 4 corners (except for where geographically unfeasible; a coastline or a border) and to have an averaged number of citizens.

    1. I love that idea, because by luck of the draw it could place both poor areas and wealthy areas in the same district.  If wealthy areas want fantastic schools then they are going to also provide them for the the children of their maids and groundskeepers as well so we all progress.

  4. Very cool! In the back of my mind, I’ve been wondering for a while if a rule like “The ratio of the area of the district to the square of the perimeter (excluding natural boundaries, like rivers and coastlines) can’t be less than 1/25” would work. (A square would have a ratio of 1/16.) I like irksome’s “four corners” rule, too.

    1. That’s better than the four corners rule because it allows for natural terrain features other than coastlines and political boundaries like city/state lines to be incorporated.

  5. Thanks for the mention. Just to clarify “Public Mapping Project” is the project “DistrictBuilder” ( is the OSS software, which was developed by the project  with software engineering and implementation services provided by Azavea ( The Azavea folks deserve a share of the credit — both for the heavy coding and for contributing a portion of the effort pro-bono.

    – Micah Altman 

    BTW — LiquidStar, DistrictBuilder should be able to handle Canada, if someone will provide the data … And the next couple of releases will add internationalization support and some other features that will make using it in other countries somewhat easier.   

  6. A better way to prevent gerrymandering would be to get rid of the district lines altogether.  Instead of lots of small single-member districts, with representatives elected in a first-past-the-post election, we could have a few large multi-member districts with representatives elected through proportional representation.

  7. An alternate simple rule for making districts saner: require them to be convex with respect to the area they are subdividing.  That is, require that they be designed such that it is impossible to draw a straight line which starts and ends in one district, but also passes through another.  Lines which start and end in a district but also pass outside the state (or whatever political unit is being subdivided) are fine (and necessary since most states aren’t convex).  This will result in district boundaries having to be few and only made of straight lines.

  8. @jere7my That’s very funny – just yesterday I was mentioning to a friend your college radio show, “Circling the Square”. =)  Assuming that’s you and not some other jere7my.

    1. That’s very funny – just yesterday I was mentioning to a friend your college radio show, “Circling the Square”. =)

      I am the only jere7my, but CtS was the conspiracy show my buddy Fred Bush did. My shows were “Off the Cuff” and “Pigs, Whither Goest”.

      Still, it’s good to be misremembered. :)

  9. I’ve been thinking of essentially the same metric, but it might make more sense to cast it as something like “the ratio of the perimeter to the square root of the area cannot exceed 5”, might be easier to remember.

  10. Two things: Calif voted down the old gerrymandering pol-party and put together a Citizens Redistricting Committee. So we’ll see. And, really Dave, “smoke-filled” back room dealmaking? More like sugar-free-gum-and-bottled-water back room dealmaking.

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