introduction.

Earlier this year, the Census Annual Population Estimates (not to be confused with the American Community Survey) released estimates that placed Chicago in an arguably very troublesome light. With an estimated loss of just under 2,900 people (about -0.11%), Chicago was predicted to have one of the biggest population losses among major U.S. cities. It was even the only one among the 10 largest cities to see any loss. This was a bit surprising as Chicago had only recently to reverse a decade-long trend of depopulation between 2000 and 2010.

Yet looking closely at the trends of population growth and loss by different groups, one trend becomes clear: Chicago’s population loss over the most recent 15 years is most significantly driven by a decline in the city’s black community. Contrary to the conventional narrative of white flight to the suburban fringe and the concentration of communities of color in the central city, census data over the last several years point to a different reality in Chicago – one of black flight, white return, and Latino displacement.

project focus.

This project seeks to build on previous research conducted on Chicago’s demographic changes. It principally seeks to broaden the scope of earlier research to examine the entirety of the Chicagoland region, as opposed to simply the city proper. I chose to focus on the entire region to more comprehensively understand regional population shifts, acknowledging that political boundaries do not reflect actual living and commuting patterns.

More specifically, I set out to explore the following themes:

• Chicago’s black population has steadily declined over the past several decades. What can regional shifts in black populations tell us about this out-migration from the central city? Are black households simply leaving Chicago or are they leaving the region entirely?
• A preliminary look at population change by income-level shows that Chicago primarily lost low- and moderate-income households, while gaining very high-income ones. How do these the trends of population change by income- or education-level play out over the entire region?

Lastly, I originally planned to also explore the relationship between local land use designations with these demographic changes (inspired by access to a regional database of land use designations by parcel). Though this is still an interest of mine, I was not able to include it in this iteration of this project.

data details.

sources. My primary data source is the U.S. Census via Brown’s Longitudinal Tract Database (BLTD). I relied heavily on the BLTD as it compiles various demographic, racial, and socioeconomic variables across the years of 1970 to 2010, all matched onto the 2010 census tract designations. This data source allowed me to accurately look at change over time. I used both Full & Sample versions of the dataset, as they allowed access to different variables. Though I did not ultimately include them, I also accessed additional data directly through the US Census API to look at more granular intersections of racial and socio-economic change (such as number of black men & women with bachelor’s degree or more per tract) and used a crosswalk file from BLTD to convert them into 2010 census tracts. Shapefiles were access through the US Census as well.

scope. For the purpose of this report, I define greater Chicagoland as the 8-county region that includes the 7-counties in Northeastern Illinois under the purview of the regional MPO (Chicago Metropolitan Planning Organization) as well as Lake County in Indiana. Two additional caveats deserve mention:

• Though I originally focused purely on the 7-county CMAP region in Illinois, I ultimately decided to also include Lake County in Indiana because (i) it quite literally abuts Chicago proper along the Illinois/Indiana border (an area affectionately known as Illiana for its blending), making it more intimately connected to the city than more recently developed exurbs, (ii) it has averaged a population of roughly 500,000 over the last 3 decades, making it a substantial part of the region, and (iii) it poses particular relevance in the study of regional black and Latino residential trends as both groups together made up almost half of the county’s population in 2010.
• In the process of conducting my data analysis, I was also struck by how much Cook County (which holds almost the entirety of Chicago itself) dominated the region’s population. To more accurately capture regional population shifts, I decided to separate out Chicago from the rest of suburban Cook County. The rest of this study thus treats Chicago as its own “county” and suburban Cook as a separate entity. Though I did not make this distinction for this project, future research may also need to distinguish between northern suburban Cook County and southern suburban Cook County – which also have very different characteristics.

A map depicting this 9 geographic differentiation is included below.

methods. Lastly, nearly all data cleaning, manipulation, and analysis occurred within Python. Other programs used include Carto (to help match tract data to shapefiles) and QGIS (to combine county shapefiles from 2 different states into one).

analysis.

I broke my analysis down into 4 parts regional racial population, spatial racial change, racial demographic change by county, and socioeconomic indicators.

i. regional racial composition by county.

First, an overall snapshot of the recent racial landscape of Chicagoland counties. The chart below shows the 2010 population of each county by race. Immediately, a couple trends are clear. First, Chicago & suburban Cook County very easily dominate the regional demographic landscape. Together they make up nearly 60% of the region’s population, and are relatively evenly populated at that. Second, Chicago unsurprisingly has the greatest numbers of Black and Latino residents, with Suburban Cook in second place. Suburban Cook, though, does have a significantly larger white population and a slightly larger Asian or Pacific Islander population. Looking at the smaller counties, most are predominantly white (especially the exurban Kendall & McHenry Counties), though Lake County (IN) does have a substantial Black community, as Kane & Lake County (IL) have a Latino one.
CHART: 2010 Population by Race & County

Looking at similar data for the 1980 census period, one other clear trend becomes apparent: all counties were substantially less diverse, though Chicago still maintained a large Black and substantial Latino community. At the regional level, almost 70% of Chicagoland-ians were white in 1980 (as compared to just over 50% in 2010).

CHART: 1980 Population by County & Race

ii. spatial racial change.

As noted above, the region saw significant racial demographic shifts over the last few decades. The following 3 maps look at these shifts at the more granular tract level for the 3 largest racial groups in Chicagoland.

white exurban sprawl + urban re-concentration. This first map examines recent change in white population by census tract. As can be seen, there are two notable patterns in white population growth: within the central city (namely, Chicago’s northern lakefront and near northwest side neighborhoods) as well as along the suburban (or exurban) regional fringe. Otherwise, most communities saw steady loss of white residents, especially the more established communities in suburban Cook County, DuPage County, and even Lake County (IN) as well.

MAP: White Population Change by Tract, 2000-2010

black flight + exurban growth nodes. In contrast to the previous map, black population change is a bit trickier to visualize due to the intense level of segregation in greater Chicago. As most census tracts do not have large populations of Black residents, they did not see significant change. The below map thus categorizes census tracts by the Natural Jenks algorithm. It depicts the depopulation that is occurring from Chicago’s South and West Sides and the concurrent growth in select parts of Kendall, Southern Cook, and central Lake (IN) Counties.

Looking at aggregate counts by geography, larger patterns in Black demographic shifts can be seen. Between 2000 and 2010, Chicago lost nearly 177,600 Black residents. The rest of the region gained almost 127,000, which suggests that black families are mostly relocating from Chicago to other parts of the region, though with a significant number also leaving. As a whole, the region lost just under 51,000 black households between 2000 and 2010 (despite still growing by 283,000).

MAP: Black Population Change by Tract, 2000-2010

Broad Latino Growth + Potential Displacement. Overall, Latino population tended to grow in the majority of census tracts. At least 75% of all census tracts in the region gained Latino residents in 2010. However, particularly strong growth was seen in the southwestern edge of Chicago, in much of Kendall County, as well as in parts of Kane. Some of the only loss of Latino residents was seen in the northwest side of Chicago, incl. communities such as Logan Square, West Town, and Humboldt Park, which have been subject to displacement pressures in recent years.

MAP: Latino Population Change by Tract, 2000-2010

iii. county-level population change by race.

Taking a step back, the charts below depict racial population change at the county-level. As stacked bars, they also depict overall population change in the county.

Several trends become apparent looking at change from 2000 to 2010. First, Chicago lost significant population, mostly driven by black depopulation. On the other hand, Suburban Cook County also just almost as many residents, though they were mostly white and offset by growth among all other racial groups. More than half of all counties in Chicagoland similarly lost white residents, suggesting a greater out-migration from the region. Similarly, though all other counties did gain Black population, Chicago’s loss of nearly 200,000 Black residents overshadowed all other gains. On the contrary, Latino and Asian/Pacific Islander communities grew in all places. Latinos even saw particularly high growth in Suburban Cook County (over 145,000), which reaffirms accounts of suburban Chicagoland’s Latino population outpacing that of the city.

CHART: Racial Change by County (2000-2010)

Taking a look further back from 1980 until 2010, slightly similar trends emerge – depicting a longer term snapshot of white flight from both Chicago and suburban Cook County. Save for Lake County in Indiana, all other non-Cook counties saw increases in White populations. Indeed, all other counties saw net increases in all racial groups.

CHART: Racial Change by County (1980-2010)

iv. socioeconomic snapshots.

Pivoting away from race, I also looked at socioeconomic indicators – beginning with income. The below boxplot examines the distribution of median household incomes of tracts within each county (incl. Chicago as a separate entity). As can be seen, several of the highest median incomes in the region come from tracts within suburban Cook County (likely among the North Shore suburbs). DuPage and Lake (IL) Counties similarly have very high-income outliers. Chicago, in contrast, has the lowest median household median income, while Kendall County has the highest concentration of higher or upper-middle class households – without any that are much lower than $50,000. McHenry County (another far suburban county) is similarly highly concentrated , while Lake County (IL) appears to have the largest spread.

CHART: 2010 Median Household Income Distribution by County

An examination of poverty levels by county, as seen below, reveals similar trends. Chicago and Lake County (IN) have the highest average poverty rates at about 22% and 20% respectively, while Kendall County has the lowest at just under 4%. In Chicago alone, half of all tracts have poverty rates above 20%. That said, Cook County does still have several high-poverty tracts. The last map below of number of college-educated adults by tract reveals parallel spatial patterns.

CHART: 2010 Population in Poverty Distribution by County

CHART: Number of College-Educated Adults by Tract in 2010

conclusions.

The maps and charts presented above show clear trends in the geography of race and class across greater Chicago. The centermost parts of the region – downtown Chicago and the city’s North side neighborhoods – are all seeing increases in white residents, more formally educated residents, and households with higher incomes. At the same time, inner-ring suburbs in outer Cook and DuPage Counties continue to experience white flight as well as general growth among Latino households. Suburbs in the southern parts of Cook County are also seeing growth in their Black populations, while the city’s historically black South and West sides continue to lose population at growing rates. At the periphery of the region, relatively more exurban counties such as Kendall and McHenry Counties are also seeing relatively fast growth among white, black and Latino residents alike.

This past week, the U.S. Census released ACS 5-year population estimates for the years covering 2011-2015. Future iterations of this project will include updated looks at recent demographic change since 2010, particularly looking at more indicators of changes in socioeconomic indicators among tracts. While tract level data allows for a thorough and granular examination of population shifts, I would also like to look at changes over time by municipality to better understand the political reality of shifting populations. Greater Chicagoland is becoming more diverse, and the concentrations of communities of color as well as low-income communities in suburban municipalities will matter for the regional equity – especially as Chicago itself (or at least the North side of it) becomes less diverse and more wealthy.