In the District of Columbia, the percent of Black teachers fell from 77 percent to 49 percent from 2003 to 2011.
The report is careful to note that it provides only descriptive figures rather than a causal explanation for the findings. But many potential theories are possible: The District of Columbia's population grew more White over this time period thanks to hyper-gentrification, possibly pushing Black teachers out into the suburbs as housing prices went up. In Cleveland, most of the loss of teachers of color occured at charter schools, the report notes, raising the possibility that the growth of those schools had an effect.
How these trends affect students also plays out differently, because of the varying demographics in the cities. In Philadelphia, the teacher-diversity gap for Black students actually closed during the period studied, despite the loss of so many Black teachers, because the number of Black students also declined.
In response to the report, AFT President Randi Weingarten called for a national summit to address teacher diversity in urban districts.
"Diversity is a key component to equality and opportunity. Where there's a diverse teaching workforce, all kids thrive. That's why we note with alarm the sharp decline in the population of Black teachers in our cities," she said.
Here's some more in-the-weeds information on the report:
How was the research conducted?
The Shanker Institute used open-records requests to gain information on the composition of the student population and the teaching force from each city's district. Because of differences in the specific data available and limitations particular to each collection, the data isn't strictly comparable from city to city. (An appendix spells out the specific methodology used to examine the results for each city.)
The data is pretty complex here, and there are a lot of ways to slice and dice it, so here are a couple of other visualizations.
Which of the districts has the greatest gap between the ethnic makeup of its teacher and student population?
That would be Philadelphia, where 31 percent of teachers are Black, Hispanic, or another race, but 86 percent of students are — a whopping 55 percentage-point difference. Following close behind are Cleveland (a 53 percentage-point diversity gap) and Boston (a 51 percentage-point gap).