Chicago Public School Enrollment Projections

November 01, 2024

Kindergarten though 12th Grade Enrollment, Historical and Projected #

K-12 enrollment has been declining in Chicago Public Schools for 24 years: from a high of 416,801 students enrolled in 2002 down to 287,957 students in 2026.

Based on 2026 enrollment and counts of Chicago births through 2023, we project that K-12 enrollment will lose another 20,000 students by the 2028-2029 school year.

Kindergarten though 12th Grade Enrollment By Race and Ethnicity, Historical and Projected #

The enrollment decline is caused by two demographic trends. First, Chicago has been losing African Americans of all ages for about twenty years. Second, the Latino baby boom peaked around 2001 and Latino births have been falling since.

Methodology #

Our projections are based on the transitions of students going from one grade to the next and the transition of children being born in Chicago too becoming kindergarteners five years later.

First, we predict enrollment in grades 1 through 12 from enrollment in the previous grade the year before. In the literature on school enrollment projections, this is called the grade progression rate method.

Second, we predict kindergarten enrollment from the number of babies born to Chicago residents five years earlier. This is called the enrollment rate method.

Thes future transitions rates are not known, so we need a plausible way of predicting them. It tends to be the case that last year’s rate is a good prediction of this year’s rate. So, for each grade-to-grade transition rate, we say that next year’s rate will be the same as this year’s rate plus or minus some random difference, and then repeat that for the following year, and so on. The size of the random differences are based on the observed historical variations. The birth to kindergarten rate moves much more from year to year than the grade-to-grade rates, as families decide between CPS, private schools, and moving away, so it gets its own, larger, random differences.

Some years also bring a temporary shock that moves many transition rates at once, like the asylum seekers who arrived in 2022 and 2023. The model includes a shock for each racial and ethnic group, and a citywide shock shared by all groups, like the pandemic drop in kindergarten enrollment in fall 2020. These shocks fade over time instead of persisting.

To make projections, we start with the observed number of students by grade and race and ethnicity and Chicago births, and use a projected transition rate to step those cohorts to next year and then we repeat that with the projected student population the following year, and then a third year. That gives us one possible trajectory of the student population. We then repeat that 1,000 times to get a range of possible trajectories.

October 2022 Updates #

• Use a weighted sample of grade transition and birth to kindergarten transitions so that transitions from recent years are more likely to be sampled than transitions from older years.
• Don’t sample transitions that had their endpoint in 2020.

August 2024 Updates #

• Added kindergarten data for 2007 and earlier.
• Reincorporated transitions that had their endpoint in 2020

October 2024 Updates #

• Change sampling weights for choosing a year’s transition rate from ∝ $({\text{year}}_i-{\text{year}}_0{)}^{1.5}$ to ∝ $2.5^{({\text{year}}_i-{\text{year}}_0)}$ to increase effect of recent years.

June 2026 Update #

Previously, projected transition rates per grade and race and ethnic group were drawn from the historically observed transition rates. This led to credible intervals that were too narrow. For this update, we switched to a random walk model for transitions.

The model also contained a per group random shock model to account for events like the asylum seekers in 2022-2023.

October 2026 Update #

• Added a citywide shock, shared by all racial and ethnic groups, alongside each group’s own shock. Previously, the groups were projected independently, which made the interval for total enrollment too narrow.
• Simulations now draw the starting transition rates and shocks together, respecting how their estimates are correlated. Drawing them independently sometimes made intervals much too wide.
• The birth to kindergarten rate now has its own random walk variance instead of sharing one with the grade-to-grade rates. Kindergarten entry varies much more, especially for white and other students.

In a backtest of one to three year forecasts made from 2010 through 2025, these changes reduced forecast error and gave intervals whose width better matched the actual errors.

Forecast Accuracy #

For each year that we make forecasts, we will record the actual total enrollment.

July 2022 Forecast #

July 2023 Forecast #

In 2022 and 2023, there was a significant immigration of Venezuelans and other asylum seekers starting.

August 2024 Forecast #

June 2026 Forecast #

Grade Data #

Chicago Public Schools publishes data on their student demographics by grade, and I’ve compiled that data into a spreadsheet.

The data has information about pre-school, but right now we are going to just look at the grade (kindergarten is coded as 0).

Unfortunately, we will also only be considering four demographic groups: non-Hispanic Blacks, Hispanics, non-Hispanic whites, and non-Hispanic other. This is because we will be using data from the Illinois Department of Public health on births and those are the only demographic groups they report.

Birth Data #

I have compiled the data for Chicago births from a number of sources. See this post for details on sources.