In light of the shootings of two police officers in Ferguson Wednesday night, we are re-posting this piece on how the racial composition of the city has changed rapidly.
The city looks significantly different now than it did 10 years ago. As Ferguson's white population has declined, its black population has increased, but unevenly. We compiled data from the Census Bureau and the state of Missouri to put together a portrait of that change.
The static maps below show the most important change, depicting the change in the density of the black population in St. Louis County between 2000 and 2012. (Full, interactive maps of St. Louis County for both years are at the bottom of the post.) The data is broken out by Census tract, with Ferguson outlined in white. (The city overlaps with parts of several tracts; thinner white lines are areas that aren't entirely Ferguson.)
The reason for the change is fairly simple. In each of the census tracts that overlap Ferguson, the white population dropped, by a total of more than 5,000 people since 2000. And in each, the black population increased, by more than 3,000.
That increased the density of the black population in each area. On average, the percentage of the six census tracts that is African American increased by 14 percentage points.
You can see in the map at the top that this was not specific to Ferguson. The entire area northwest of the city of St. Louis became more heavily black; Ferguson was simply part of that.
Which brings us to the police. As many outlets have noted, there has been a consistent discrepancy between the extent to which whites and blacks have been arrested by the Ferguson Police Department.
In 2000, whites comprised a slightly larger percentage of the population, but were just over a third of the police stops and only one-fifth of the arrests. By 2013, blacks were in the majority, and the gap between black and white stops and arrests grew. In other words, before the population shift, there was a disproportionate focus by Ferguson police on blacks. After the population shift, it became more stark.
At the same time, the composition of the police force is heavily white — 50 white officers to three black. As Megan McArdle notes at Bloomberg View, there's a possible explanation. While the population changed, it's likely that the police force changed more slowly. While a 50-to-3 ratio would not have been representative of the population in 2000, and while the city's mayor protests that the police have hired "everyone that we can get," it almost certainly got more misrepresentative as the population changed. (We called the Ferguson Police Department to try and ascertain the average length of service of its officers; the department's spokesperson's voice mail was not accepting new messages.) As Ferguson moved in one direction, the police force didn't.
Countless municipalities change and grow and evolve over time without tension erupting. But it's not hard to see why tension between an increasingly black population and a very white police force would emerge after an incident like the death of Michael Brown at the hands of an unnamed officer.