Racial Residential Segregation

Last Updated: 
Jan 13, 2022

Racial segregation is declining but still present in the region.

The central Puget Sound region's housing landscape reflects more than just market forces and conditions. It is also the product of decades of public policies and private practices that served to exclude people of color from accessing housing and living in all communities.

On this page, PSRC maps residential settlement patterns across the region by race, explores the various causes of racial residential segregation that contributed to these patterns, and offers data resources for analyzing segregation and its relationship to opportunity access.

Racial Settlement Patterns in the Region

Using data from the 2020 Census, these maps illustrate the distinct settlement patterns of the region's population across racial and ethnic groups.

Causes of Residential Segregation

There are many factors contributing to racially segregated patterns of settlement, which can be classified into three categories.


Refers to the dynamic in which people co-locate with others of similar racial or ethnic backgrounds based on personal preferences and cultural affinities. This can include, for example, neighborhoods established by immigrant and other people of color populations that serve as cultural hubs for local businesses, civic institutions, shared language, and community. Evidence suggests, however, that decisions to co-locate are shaped by additional factors that limit available housing choices for people of color and lower-income households.

Active Segregation

Refers to discriminatory policies and practices that produce and reinforce racial segregation across neighborhoods. Examples include restrictive residential deed covenants and redlining, which were common mid-twentieth century ownership restrictions and lending rules that prohibited people of color from living in particular neighborhoods. Contemporary bias in real estate and lending practices persist, which perpetuates racial disparities created by these historical discriminatory policies.

The links below provide additional details about past and present discriminatory policies and practices:

Structural Segregation

Describes the racial sorting that results from structural inequalities in society. The correlation between race and income translates to spatial segregation as people of color are concentrated in neighborhoods, in part, because of lower incomes. High-priced neighborhoods as well as neighborhoods with limited rental housing fail to provide feasible or welcoming housing choices for low and moderate income households who are disproportionately people of color.

Dissimilarity Index - A Measure of Residential Segregation

The dissimilarity index helps us to understand the degree of racial residential segregation in the region.

Table showing dissimilarity index values by decade and race. Low, moderate, and high levels of segregation are color coded. For more information, contact the PSRC Information Center at 206-464-7532.

Background and Analysis

Several quantitative metrics are available to measure the degree of residential segregation present in a city, county, or region. One of the most common used by social scientists is the dissimilarity index.

The index measures evenness in the distribution of two demographic groups across neighborhoods within a broad geographic area. The index value represents the proportion of one group that would need to move for all neighborhoods to match the composition of the broader area.

Based on guidelines drafted by the U.S. Department of Housing and Urban Development, an index value of 0.40 or below indicates “low” levels of segregation, a value between 0.41 and 0.54 indicates “moderate” levels of segregation, and a value of 0.55 or above indicates “high” levels of segregation.

PSRC produced the regional dissimilarity indices above as an update to analysis originally conducted as part of the Fair Housing and Equity Assessment (2014). The indices are calculated for five different demographic pairings: white-American Indian and Alaska Native, white-Asian, white-Black, white-Hispanic or Latinx, and white-people of color.

Compared to other major metro areas across the U.S., the central Puget Sound is generally characterized by low to moderate levels of segregation. And consistent with national trends, levels of segregation have declined modestly over the last two decades for Black and Hispanic or Latinx populations.

But residential segregation continues to exist and is more pronounced for some demographic groups than others. Indices based on 2020 Census data show that the region’s Black population continues to experience substantially higher levels of segregation than people of color in general.

The historic data comparison further tells us that segregation levels have not improved for American Indian and Alaska Native populations and Asian populations; there has been a slight uptick in segregation for these populations. 

Download Data

Download the data file of regional dissimilarity indices, including data inputs and calculations at the neighborhood (i.e. census tract and block group) level.

Regional Dissimilarity Indices [.xlsx]

Segregation and the Geography of Opportunity

Looking at patterns of residential segregation in relation to access to opportunity helps us better understand how segregation may benefit or burden different communities.

Background and Analysis

A vast body of research points to residential segregation as a leading driver of racial inequities in education, employment, income and wealth, health outcomes, and more. Racially and economically segregated communities are shown to have significantly reduced access to resources and opportunities that allow people to thrive and reach their highest potential, preventing the region from achieving its goal of racial equity.

The regional Opportunity Mapping tool – developed in partnership with The Ohio State University’s Kirwan Institute as part of PSRC’s Growing Transit Communities program, and updated as part of the VISION 2050 planning process – is a research tool for mapping and analyzing the dynamics of opportunity within our region.

The mapping tool is based on an “opportunity index” developed using multiple neighborhood-level data sources selected to represent opportunity and life outcomes in five key areas: education, economic health, housing and neighborhood quality, mobility and transportation, and health and environment.

The data are combined into a single composite index that tells us where each neighborhood lies on the regional spectrum of opportunity. The index values have been classified into five opportunity categories: “very high,” “high,” “moderate,” “low,” and “very low.”

Access to Opportunity

PSRC tested the statistical relationship between geographic patterns of opportunity and racial residential segregation in the region and found that neighborhoods that are disproportionately white or Asian compared to the regional average generally correspond with higher access to opportunity, while neighborhoods that are disproportionately Black, Hispanic or Latinx, or American Indian and Alaska Native correspond with lower access to opportunity.

Note that the Asian population represents an extremely diverse demographic category. The recently published 2021 Central Puget Sound Demographic Profile observes that while the Asian population as a whole has a relatively low poverty rate and the highest median household income across all racial and ethnic origin groups, there is considerable variation within this racial category depending on country of origin and length of time in the U.S. Lower-income Asian groups including many refugee communities and immigrant populations arriving without skills based visas are likely to experience housing barriers, segregation, and limited access to opportunity at levels similar to other marginalized communities of color.

Regional Policies and Strategies to Address Racial Residential Segregation

Together, past and current discriminatory housing practices have perpetuated substantial inequities in housing choices and opportunity and continue to create barriers to rectifying these conditions. VISION 2050 recognizes this legacy and of the comprehensive work needed to redress it.

PSRC is working to develop data analysis, resources, and guidance to support the implementation of strategies to address racial residential segregation and disparate access to opportunity.