The FRED Blog frequently provides context to help tell the story behind the data. Today we need a bit of history as well to help clarify the names of the data series themselves.
In 1876, the city of St. Louis, Missouri, became its own county, separating its local government affairs from the rest of St. Louis County, Missouri. Since then, the U.S. Census has tallied population statistics across subdivisions, or tracts, of these two separate counties with very similar names.
The FRED graph above shows the racial dissimilarity index for St. Louis City (in blue) and St. Louis County (in red). The Census reports the index as a percent of the non-Hispanic White population that would have to move from one census tract in a county to another census tract in the same county to achieve an even distribution of racial groups across that county.
Consider 2009, when the first data in the series are available: At that time, about two out of every three non-Hispanic White residents in the city of St. Louis would have had to change where they lived for this specific type of racial dissimilarity to disappear within St. Louis City. Slightly more than half of the residents in St. Louis County would have had to do the same to eliminate this racial dissimilarity in that county.
Twelve years later, the population landscape has changed. Since 2020, in terms of their racial makeup, the tracts in St. Louis City are noticeably more like one another than the tracts in St. Louis County.
However, the overall racial makeup of these two similarly named neighboring counties is very different and should be taken into consideration when interpreting the data. To begin with, almost two out of every three County residents are non-Hispanic White. In the City, the ratio is almost one-to-one. The population trends are also different: Between 2010 and 2020, the city lost almost 6% of its residents, while the county added 5%.
So, at least two different population trends could be at play here. Perhaps, on average, neighborhoods in the City are becoming more racially integrated while neighborhoods in the County remain steadfastly less integrated. Or it could be that population loss of racial minorities in some City neighborhoods is making the overall racial distribution there more even. Of course, both trends can be at play here. An in-depth analysis of tract-level Census data is needed to come to a definite conclusion.
How this graph was created: In FRED, search for “White to Non-White Racial Dissimilarity (5-year estimate) Index for St. Louis city, MO.” Next, click “Edit Graph” at the top right corner and navigate to the “Add Line” tab. Search for “White to Non-White Racial Dissimilarity (5-year estimate) Index for St. Louis County, MO” and click on “Add data series.”
Suggested by Diego Mendez-Carbajo.
