The Pro Bono Thinking Society

PBTS3: New Wards of Chicago

Status: Complete

REPORT (updated November 3rd, 2011)

PBTS Project #3
Title: New Wards of Chicago
Start Date: 9/6/11
Report Date: 11/2/11

I. Summary of the problem
The City of Chicago is tasked to redraw its ward map by the end of 2011. The ward redistricting process is one that is difficult at any political level, and the City of Chicago is no exception. Ward redistricting influences the political landscape for years but is also subject to interests and actions that do not directly benefit the public. In the past, ward redistricting has been influenced by two aims that have little benefit to the general public: ensuring incumbent power and divvying up wards based on race. The result is a map with oddly shaped wards that often do not represent real community areas and sacrifice efficient delivery of information and city services for the sake of political gain.

“From a cost-efficiency standpoint, the ward system over time made less and less sense because each successive gerrymandering of the ward maps carved up communities and shredded natural boundaries: main arterial streets, parks, and the like.” -Source

For example:

Wards like those above are what we’re fighting against. Our research and findings follow.

II. Initial research
In starting this project, we hoped to answer the question: “What would the new ward map look like if it was drawn by a completely independent group with no skin in the game?”

We decided to look purely at total population data at the census tract level and ignore any data on race, socioeconomic status, or voting history. We found discussions of “white wards” and “hispanic wards” and “black wards” to be focused on a past that should no longer exist in the City of Chicago. A ward should be designed to represent a geographical community area within the city, not race. As the first Asian alderman, would anyone claim that Ameya Pawar of the north side 47th ward represents the Asian population of Chinatown? Would a white alderman representing Lakeview serve the same interests as a white alderman in Bridgeport? We felt it was time the redistricting process focused on clearly defined, compact wards that were based on intact census tracts rather than gerrymandered blocks.

Wards should be based on geographical boundaries (such as roads, waterways, public spaces), and general community areas, with the aim of being as compact and easily identifiable as possible. Wards should not be created based on race, political implications, or for the benefit of any individual or individual group. Using census tract level data helps achieve several of these objectives, as census tracts themselves are designed to be relatively compact and follow common sense boundaries:

“The Following Features are Preferred as Census Tract Boundaries for the 2010 Census:
c. Visible, perennial natural and cultural features, such as roads, shorelines, rivers, perennial streams and canals, railroad tracks, or above-ground high-tension power lines.” -Source

In addition, using existing tract boundaries to form ward boundaries helps ensure consistency and stability as tract boundaries are intended to be as permanent as possible:

“Pursuant to this goal of continuity and comparability, the Census Bureau requests that where a census tract must be updated, for example to meet the minimum or maximum population or housing unit thresholds, that the outer boundaries of the tract not be changed, but rather that a tract be split into two or more tracts, or merged with an adjacent tract.” -Source

From a similar redistricting effort in Washington D.C.:

“Why do Census tracts matter? For one, the law requires redistricting to try to keep Census tracts together. The current committee seems to have ignored that dictate. Also, a great deal of data is reported on the Census tract level. When government agencies compute statistics for wards, they save time and money if ward boundaries primarily conform to tracts.” -Source

We obtained our data from the U.S. Census American FactFinder and the City of Chicago’s Data Portal 2.0. In addition, Steven Romalewski of CUNY Mapping Service at the Center for Urban Research provided us with helpful suggestions for data sources.

III. Recommended solution
First, our map, followed by new ward data (including race for those that are interested):

An interactive version of the map can be explored here.

The result is a Chicago ward map with much more compact and easily identifiable wards, relatively even population numbers across wards, and the removal of all gerrymandering “spider legs”. Zero census tracts were divided, meaning tract level data can be applied quickly and easily to wards. Delivery of some city services should become more efficient due to the more compact wards. (Although additional efforts are encouraged).

As a final note, let us revisit a few of the more interesting wards from the past ten years:

This map isn’t perfect, and we look forward to hearing how it can be improved. We feel strongly about the principles that guided this exercise and we hope it contributes in some way to the public discourse. We’ve included our master data set, our master shapefiles and a summary of ward populations.. You can even download a blank map with census tract population data included so you can draw your own wards.

PBTS Proposed Map (color) – PDF (338KB)
Current Wards Map – PDF (1.1MB)
Master Data File – XLS (319KB)
All Shape Files – ZIP (1MB)
Color Your Own Wards – PNG (3.2MB)

To get a more detailed view of each ward, we have an interactive map here.

If you’d like to access to any additional data or map files that we’ve used, please do not hesitate to contact us at You can also reach us on Twitter at  @probonothinking. We look forward to any feedback.

If you or your organization could use a little help solving a problem, feel free to submit a topic to The Pro Bono Thinking Society. Our only promise is an independent, unbiased, and honest effort.


BRIEFING (updated September 6th, 2011)

The City of Chicago is set to redraw its ward map by the end of the year, a once-in-a-decade task that will alter the political landscape for the foreseeable future. With so much at stake, there is great potential for bias and gamesmanship in the redistricting process. An independent, thoughtful, and unbiased ward map proposal is needed.


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