The Persistent Effects of Redlining in Baltimore

In the late 1930s, the Home Owners’ Loan Corporation (HOLC) created “residential security maps” for over 200 American cities as part of the federal government’s program of housing and mortgage relief. These maps analyzed the level of risk of lending for mortgages (and similar services such as homeowners’ insurance) in various neighborhoods within each city, with a scale running Green (most desirable), Blue, Yellow, Red (hazardous). The criteria by which each neighborhood was graded included the quality and state of repair of the housing, average neighborhood income. Often most significant, however, was the racial and ethnic make-up of the neighborhood: the presence of African American residents or other “undesirable” ethnic groups such as Mexicans, Italians, or Jews, had severely negative impacts on a neighborhood’s classification. In particular, practically all neighborhoods that were predominantly African American were given yellow or red grades. Although the direct use of these maps was effectively outlawed by the 1968 Fair Housing Act, the maps created patterns of disinvestment in nonwhite neighborhoods continue to shape U.S. cities to this day. One of those cities, which will be studied here, is Baltimore.

This work aims to identify the discrepancies among those areas historically subject to redlining in Baltimore and with the overall city with regards to race, income, and lethal violence.

Aim 1: Explore the relation between the pattern of disinvestment in redlined neighborhoods in Baltimore and the contemporary incomes of those neighborhoods. Approach: Census block group level data was collected for household income in Baltimore City, and mean incomes calculated. The borders and classifications of HOLC-rated districts in the city were collected from the University of Richmond’s Mapping Inequality project. Using ArcGIS Pro, these were superimposed, and the mean income of the redlined districts was estimated based on the block-group level data. Descriptive statistics were calculated between districts and with the city at large.

Aim 2: Explore the relation between the pattern of racial segregation in redlined neighborhoods in Baltimore and the demographics of those neighborhoods. Approach: Census block-group level data was collected for racial background in Baltimore City, and mean incomes calculated. The borders and classifications of HOLC-rated districts in the city were collected from the University of Richmond’s Mapping Inequality project. Using ArcGIS Pro, these were superimposed, and the racial demographics of the redlined districts was estimated based on the block-group level data. Descriptive statistics were calculated between districts and with the city at large.

Aim 3: Explore the relation between those redlined neighborhoods and the contemporary problems of violence in Baltimore. Approach: Data on publicly reported police killings were collected from the Mapping Police Violence database, and data on homicides in Baltimore were collected from the Baltimore Sun’s Baltimore Homicides project. These incidents were individually mapped as points using ArcGIS Pro, and geographic patterns were explored and visualized using a raster map for homicides. Numbers of police killings and homicides were summarized for each redlined district, and descriptive statistics comparing those districts across grades and to the city at large were calculated.

To study the racial impacts of redlining, US Census data for race by block group throughout the city was mapped. Block-groups within the districts graded by HOLC were then averaged to reveal the composition of each district as a whole.

The mapping revealed that while some correlation between historically redlined or yellow-lined districts and concentrations of people of color in the city persists, these patterns are less distinct than might be expected given the segregationist history of redlining practices. As can be seen in Fig. 1, several districts that were green-lined or blue-lined are now more than 90% non-white, while some redlined districts are now less than 25% people of color. These population changes can likely be attributed to several historical trends: white flight from the city from the 1950s to 1970s, 1960s and 1970s blockbusting in formerly segregated white neighborhoods, and the massive forcible displacement of African American residents by midcentury urban renewal projects, particularly in the formerly redlined areas impacted by Charles Center and the Inner Harbor.

As Table 1 shows, however, there is a fairly clear pattern in which areas given lower HOLC grades continue to have higher proportions of ethnic minorities: only formerly green-lined areas, and redlined areas (where urban renewal displacements were concentrated), have non-white populations below the mean for a city block-group.

The mapping (fig. 2) suggests that the cycle of disinvestment in redlined and yellow-lined neighborhoods has been particularly persistent. The city’s highest-income areas (those where the mean annual household income exceeds $100,000) are exclusively in green-lined, blue-lined, or ungraded districts. On average, green-lined and blue-lined districts have mean incomes roughly $24,000 and $17,000 higher than the average block group in the city. Meanwhile, the average yellow-lined district has a mean income $11,000 lower than the mean block group, and the average redlined district only rises above the mean block group because a district which no longer has any residents was excluded, while the sole redlined district with a mean household income above $75,000 is itself in many ways a historical outlier due to being the site of the Inner Harbor and other renewal efforts.

This suggests that historic redlining continues to be reflected in income disparity between neighborhoods today.

Redlining, among other segregationist urban policies of the twentieth century, often produced neighborhoods mired in cycles of poverty and physical disrepair, both of which have been suggested as causal factors for higher rates of crime. Contemporary Baltimore has relatively high rates of both homicide and killings by police; these are critical issues for the city.

The correlation between areas with large numbers of homicides, as shown by the homicide heat map, and areas which were formerly redlined or yellow-lined by the Home Owners’ Loan Corporation is particularly striking. All areas with especially high homicide rates (over the past 14 years) are largely or wholly within or surrounded by redlined or yellow-lined districts. While the concentration of killings by police is less immediately visible, fully 74% of those killings since 2013 took place in redlined or yellow-lined districts. (This is actually in slight contrast to homicides, only 64% of which took place in those districts).

Tables 3 and 4 suggest that, as with both race and income, redlined districts overall have actually had somewhat lower rates of lethal violence than yellow-lined ones, likely due once again to the historic forces of urban renewal projects etc. displacing and destroying the historic neighborhoods and populations that were originally redlined. (Those projects of erasure were repeatedly concentrated in majority-African American neighborhoods).

This cannot obscure, however, that more police killings took place in redlined areas alone than in green, blue, and ungraded areas combined, and more homicides took place in redlined areas than in green and blue districts combined. Clearly the preponderance of lethal violence in modern Baltimore remains concentrated in redlined and yellow-lined neighborhoods.

As this analysis demonstrates, the historic phenomenon of redlining continues to have a significant impact on the fate of Baltimore neighborhoods today. The city’s white population generally remains concentrated outside of districts given low grades by HOLC in the 1930s. Mean household incomes in yellow-lined areas remain below that of the mean block-group, while mean incomes in green-lined and blue-lined districts remain above it. Strikingly, lethal violence in the city – in the form of both homicides and police killings – is incredibly concentrated in yellow-lined and red-lined districts. Where these trends are attenuated, there is a clear historic cause in the form of major historic events – white flight and blockbusting increasing the non-white share of the urban population, urban renewal in the Inner Harbor displacing the poor African American majority neighborhoods that were originally redlined – that suggest some districts would be best understood as outliers.

           The consequences of redlining are still alive in Baltimore today.