Distribution of the population by race/ethnic group within a census tract relative to the distribution across the city (index)

The geographic distribution of racial/ethnic groups across a city can play a key role in understanding health differences <sdt id="1458753441" sdttag="goog_rdk_9">among </sdt>groups. In many communities, long standing practices by banks, the real estate industry, the judicial system, and more have contributed to patterns of residential segregation and unequal resource allocation that endure to this day.1,2 These lasting effects are seen most saliently in Black-White geographical divides.3 Research shows that Black persons in particular who live in <sdt id="-1902354147" sdttag="goog_rdk_12">racially </sdt>segregated communities are more likely to experience economic segregation, leading to limited employment opportunities and lower incomes.4 In addition, they may experience increased risk of <sdt id="-261219832" sdttag="goog_rdk_13">poor health </sdt>outcomes such as adverse birth <sdt id="-27252248" sdttag="goog_rdk_15"></sdt>effects, cardiovascular disease, and cancer fatalities <sdt id="1800027721" sdttag="goog_rdk_16">– </sdt>results that may be attributed to limited access to health resources and the effects of racist structures.2,5,3,6 However, in certain communities with similar rates of segregation, stronger social bonds may counteract these effects and instead promote positive health outcomes, such as increased support for cancer prevention.7

Research for the effects of segregation among Hispanic and Asian communities is less robust – scholars have called for more thorough studies across demographic groups, not just Black and White<sdt id="815228116" sdttag="goog_rdk_18"> groups</sdt>.8<sdtpr></sdtpr><sdt id="1603990845" sdttag="goog_rdk_19">Available research</sdt><sdtpr></sdtpr><sdt id="36943266" sdttag="goog_rdk_21">shows </sdt>mixed conclusions. For example, there is evidence that living in an ethnic enclave may increase breast cancer survival rates among Latinas, while another study shows that Hispanics living in low socioeconomic and ethnically homogenous areas have higher rates of cervical cancer incidence.9,10 Similarly, the effects of ethnic enclaves for Asian communities vary, providing social support in some instances but potentially <sdtpr></sdtpr><sdt id="220567720" sdttag="goog_rdk_24">increasing </sdt>rates of cognitive decline in others.11-13 Overall, patterns of residential segregation are not the same across cities, resulting in an array of health <sdtpr></sdtpr><sdt id="-1236073587" sdttag="goog_rdk_26"></sdt>effects between racial/ethnic groups.14

Neighborhood racial/ethnic segregation (also known as the Entropy Index as well as Theil’s H) measures the extent to which a city’s racial/ethnic groups are geographically clustered. Neighborhood racial/ethnic segregation is represented on a scale from 0 to 100<sdt id="1396782492" sdttag="goog_rdk_39">,</sdt> where lower values indicate less segregation. A value of 0 indicates no segregation: <sdt id="-505437463" sdttag="goog_rdk_40">A</sdt>ll racial/ethnic groups are represented equally across all census tracts. A value of 100 indicates absolute segregation – all racial/ethnic groups reside in separate census tracts. 

<a name="_heading=h.30j0zll" id="_heading=h.30j0zll"></a>The Dashboard measures both segregation and <sdt id="-425260700" sdttag="goog_rdk_46"></sdt><a href="/metric/racialethnic-diversity" target="_blank">diversity</a>. A particular city could be quite diverse, populated by many racial/ethnic groups, but members of these groups could be segregated into different neighborhoods. Alternatively, a city can be without significant residential segregation, but also have low diversity. Thus, it is important to consider both measures.

For those seeking to understand the distinction between how we measure diversity and segregation further check out <a href="https://www.cityhealthdashboard.com/story/860">our blog</a> for more information!

<a name="_heading=h.1fob9te" id="_heading=h.1fob9te"></a>NOTE: Within our Dashboard metrics, we categorize race/ethnicity into the following five categories: Asian (Asian and Pacific Islander); Black/African American; Other (American Indian and Alaska Native, two or more races, and some other race); Hispanic; and non-Hispanic White. This is due to data availability and calculation constraints. Consult our <a href="/technical-documentation" target="_blank">Technical Documentation</a> to learn more.

<table border="1" cellpadding="1" cellspacing="1"><tbody><tr><td>Strengths of Metric</td>
			<td>Limitations of Metric</td>
		</tr><tr><td>
			<ul><li>Unlike other measures of segregation, which often analyze the proportion of only two racial/ethnic groups in a geographic area, neighborhood racial/ethnic segregation can account for the presence of multiple racial/ethnic groups.15</li>
				<li>Neighborhood racial/ethnic segregation measures the “evenness” of the distribution of racial/ethnic groups within an area. This is one of the most popular and validated measures of segregation in academic literature.16,17 (Massey, 1988 #806; Massey, 1988 #806)</li>
			</ul></td>
			<td>
			<ul><li>Racial/ethnic segregation does not specify which racial/ethnic groups are segregated.</li>
				<li>This metric is limited to mutually exclusive subgroups, due to how it is calculated. This means that not all races and ethnicities are distinctly reflected within the metric, as they are instead grouped into the category of "other." This obscures some intricacies of a community's racial/ethnic composition.</li>
				<li>There are no inherently good or bad values of segregation: The local context along with other contributing data of neighborhoods and cities, must be taken into account when interpreting these estimates. </li>
				<li>This metric does not address the structural and systemic causes of segregation.</li>
			</ul></td>
		</tr></tbody></table>

Segregation is quantified as per Iceland’s formula for H, the entropy index, which uses smaller geographies (such as tracts) to calculate scores for larger geographies (such as cities). The equation for H provides a raw value between 0-1. The segregation (entropy index) values that are presented on the Dashboard represent H*100 to provide segregation scores that range from 0 to 100.

For more information on the calculation, please refer to Iceland’s publication15 and the <a href="https://cityhealthdashboard.com/page/823">City Health Dashboard Technical Document</a>.

Estimates for these metrics are from <a href="https://www.census.gov/programs-surveys/acs/">American Community Survey</a> 5-year estimate data using the DP05 table. Multi-year data are available for these metrics. For more information, please refer to <a href="/multi-year-data">Using Multi-Year Data: Tips and Cautions</a>.

<ol><li>
	Massey DS, Denton NA. American apartheid: Segregation and the making of the underclass. Harvard University Press; 1993.
	</li>
	<li>
	Williams DR, Collins C. Racial residential segregation: a fundamental cause of racial disparities in health. Public health reports (Washington, DC : 1974). Sep-Oct 2001;116(5):404-16. doi:10.1093/phr/116.5.404
	</li>
	<li>
	Kershaw KN, Albrecht SS, Carnethon MR. Racial and ethnic residential segregation, the neighborhood socioeconomic environment, and obesity among Blacks and Mexican Americans. Am J Epidemiol. Feb 15 2013;177(4):299-309. doi:10.1093/aje/kws372
	</li>
	<li>
	Kramer MR, Hogue CR. Is segregation bad for your health? Epidemiol Rev. 2009;31:178-94. doi:10.1093/epirev/mxp001
	</li>
	<li>
	Mehra R. Racial residential segregation and adverse birth outcomes: A systematic review and meta-analysis. Social Science and Medicine. 2017;doi:10.1016/j.socscimed.2017.09.018
	</li>
	<li>
	Landrine H. Residential Segregation and Racial Cancer Disparities: A Systematic Review. Journal of Racial and Ethnic Health Disparities. 2016;doi:10.1007/s40615-016-0326-9
	</li>
	<li>
	Kruse-Diehr AJ. Racial Residential Segregation and Colorectal Cancer Mortality in the Mississippi Delta Region. Preventing Chronic Disease. 2021;doi:10.5888/pcd18.200483
	</li>
	<li>
	Do DP. Hispanic Segregation and Poor Health: It's Not Just Black and White. American Journal of Epidemiology. 2017;186(8):990-999. doi:<a href="https://doi.org/10.1093/aje/kwx172">https://doi.org/10.1093/aje/kwx172</a>
	</li>
	<li>
	Shariff-Marco S. Nativity, ethnic enclave residence and breast cancer survival among Latinas: variations between California and Texas. Cancer. 2020;126(12):2849-2858. doi:10.1002/cncr.32845
	</li>
	<li>
	Froment M-A. Impact of socioeconomic status and ethnic enclave on cervical cancer incidence among Hispanics and Asians in California. Gynecol Oncology. 2014;133(3):409-415. doi:10.1016/j.ygyno.2014.03.559
	</li>
	<li>
	Guo M. Ethnic enclaves, social capital, and psychological well-being of immigrants: the case of Chinese older immigrants in Chicago. Aging and Mental Health. 2022;doi:<a href="https://doi.org/10.1080/13607863.2022.2084506">https://doi.org/10.1080/13607863.2022.2084506</a>
	</li>
	<li>
	Guo M. Is Living in an Ethnic Enclave Associated With Cognitive Function? Results From the Population Study of Chinese Elderly (PINE) in Chicago. Gerontologist. 2022;62(5):662-673. doi:10.1093/geront/gnab158
	</li>
	<li>
	Lim S. Defining Ethnic Enclave and Its Associations with Self-Reported Health Outcomes Among Asian American Adults in New York City. Journal of Immigrant and Minority Health. 2017;19(1):138-146. doi:10.1007/s10903-015-0334-6
	</li>
	<li>
	Darden JT. Racial residential segregation and the concentration of low- and high-income households in the 45 largest U.S. metropolitan areas. Journal of Developing Societies. 1997;13(2):171-94.
	</li>
	<li>
	Iceland J. The multigroup entropy index (also known as Theil’s H or the Information Theory Index). US Census Bureau. Accessed June 14, 2023, <a href="https://www2.census.gov/programs-surveys/demo/about/housing-patterns/multigroup_entropy.pdf">https://www2.census.gov/programs-surveys/demo/about/housing-patterns/multigroup_entropy.pdf</a>
	</li>
	<li>
	Massey DS, Denton NA. The Dimensions of Residential Segregation. Social Forces. 1988;67(2):281-315. doi:10.2307/2579183
	</li>
	<li>
	Bureau USC. Theil Index. website. Updated October 8, 2021. 2023. <a href="https://www.census.gov/topics/income-poverty/income-inequality/about/metrics/theil-index.html#:~:text=The%20Theil%20index%20is%20a,everyone%20having%20the%20same%20income">https://www.census.gov/topics/income-poverty/income-inequality/about/metrics/theil-index.html#:~:text=The%20Theil%20index%20is%20a,everyone%20having%20the%20same%20income</a>.
	</li>
</ol>Last updated: July 27, 2023

Neighborhood Racial/Ethnic Segregation

Distribution of the population by race/ethnic group within a census tract relative to the distribution across the city (index)

Why do we measure neighborhood racial/ethnic segregation?

How do we measure neighborhood racial/ethnic segregation?

Strengths and Limitations

Calculation

Data Source

References